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mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: move some shrinker-related function declarations to mm/internal.h Patch series "cleanups for lockless slab shrink", v4. This series is some cleanups for lockless slab shrink. This patch (of 4): The following functions are only used inside the mm subsystem, so it's better to move their declarations to the mm/internal.h file. 1. shrinker_debugfs_add() 2. shrinker_debugfs_detach() 3. shrinker_debugfs_remove() Link: https://lkml.kernel.org/r/20230911092517.64141-1-zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/20230911092517.64141-2-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian König <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Price <steven.price@arm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Sean Paul <sean@poorly.run> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:25:14 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinker: remove redundant shrinker_rwsem in debugfs operations debugfs_remove_recursive() will wait for debugfs_file_put() to return, so the shrinker will not be freed when doing debugfs operations (such as shrinker_debugfs_count_show() and shrinker_debugfs_scan_write()), so there is no need to hold shrinker_rwsem during debugfs operations. Link: https://lkml.kernel.org/r/20230911092517.64141-4-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian König <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Price <steven.price@arm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Sean Paul <sean@poorly.run> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:25:16 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" This reverts commit 20cd1892fcc3efc10a7ac327cc3790494bec46b5. Kernel test robot reports -88.8% regression in stress-ng.ramfs.ops_per_sec test case [1], which is caused by commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless"). The root cause is that SRCU has to be careful to not frequently check for SRCU read-side critical section exits. Therefore, even if no one is currently in the SRCU read-side critical section, synchronize_srcu() cannot return quickly. That's why unregister_shrinker() has become slower. We will try to use the refcount+RCU method [2] proposed by Dave Chinner to continue to re-implement the lockless slab shrink. So revert the shrinker_srcu related changes first. [1]. https://lore.kernel.org/lkml/202305230837.db2c233f-yujie.liu@intel.com/ [2]. https://lore.kernel.org/lkml/ZIJhou1d55d4H1s0@dread.disaster.area/ Link: https://lkml.kernel.org/r/20230609081518.3039120-5-qi.zheng@linux.dev Reported-by: kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/oe-lkp/202305230837.db2c233f-yujie.liu@intel.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 08:15:15 +00:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" This reverts commit 20cd1892fcc3efc10a7ac327cc3790494bec46b5. Kernel test robot reports -88.8% regression in stress-ng.ramfs.ops_per_sec test case [1], which is caused by commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless"). The root cause is that SRCU has to be careful to not frequently check for SRCU read-side critical section exits. Therefore, even if no one is currently in the SRCU read-side critical section, synchronize_srcu() cannot return quickly. That's why unregister_shrinker() has become slower. We will try to use the refcount+RCU method [2] proposed by Dave Chinner to continue to re-implement the lockless slab shrink. So revert the shrinker_srcu related changes first. [1]. https://lore.kernel.org/lkml/202305230837.db2c233f-yujie.liu@intel.com/ [2]. https://lore.kernel.org/lkml/ZIJhou1d55d4H1s0@dread.disaster.area/ Link: https://lkml.kernel.org/r/20230609081518.3039120-5-qi.zheng@linux.dev Reported-by: kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/oe-lkp/202305230837.db2c233f-yujie.liu@intel.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 08:15:15 +00:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: add scan interface for shrinker debugfs Add a scan interface which allows to trigger scanning of a particular shrinker and specify memcg and numa node. It's useful for testing, debugging and profiling of a specific scan_objects() callback. Unlike alternatives (creating a real memory pressure and dropping caches via /proc/sys/vm/drop_caches) this interface allows to interact with only one shrinker at once. Also, if a shrinker is misreporting the number of objects (as some do), it doesn't affect scanning. [roman.gushchin@linux.dev: improve typing, fix arg count checking] Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon [akpm@linux-foundation.org: fix arg count checking] Link: https://lkml.kernel.org/r/20220601032227.4076670-7-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:27 -07:00
Revert "mm: shrinkers: make count and scan in shrinker debugfs lockless" This reverts commit 20cd1892fcc3efc10a7ac327cc3790494bec46b5. Kernel test robot reports -88.8% regression in stress-ng.ramfs.ops_per_sec test case [1], which is caused by commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless"). The root cause is that SRCU has to be careful to not frequently check for SRCU read-side critical section exits. Therefore, even if no one is currently in the SRCU read-side critical section, synchronize_srcu() cannot return quickly. That's why unregister_shrinker() has become slower. We will try to use the refcount+RCU method [2] proposed by Dave Chinner to continue to re-implement the lockless slab shrink. So revert the shrinker_srcu related changes first. [1]. https://lore.kernel.org/lkml/202305230837.db2c233f-yujie.liu@intel.com/ [2]. https://lore.kernel.org/lkml/ZIJhou1d55d4H1s0@dread.disaster.area/ Link: https://lkml.kernel.org/r/20230609081518.3039120-5-qi.zheng@linux.dev Reported-by: kernel test robot <yujie.liu@intel.com> Closes: https://lore.kernel.org/oe-lkp/202305230837.db2c233f-yujie.liu@intel.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 08:15:15 +00:00
mm: shrinkers: add scan interface for shrinker debugfs Add a scan interface which allows to trigger scanning of a particular shrinker and specify memcg and numa node. It's useful for testing, debugging and profiling of a specific scan_objects() callback. Unlike alternatives (creating a real memory pressure and dropping caches via /proc/sys/vm/drop_caches) this interface allows to interact with only one shrinker at once. Also, if a shrinker is misreporting the number of objects (as some do), it doesn't affect scanning. [roman.gushchin@linux.dev: improve typing, fix arg count checking] Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon [akpm@linux-foundation.org: fix arg count checking] Link: https://lkml.kernel.org/r/20220601032227.4076670-7-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:27 -07:00
mm: shrinker: use min() to improve shrinker_debugfs_scan_write() Use the min() macro to simplify the shrinker_debugfs_scan_write() function and improve its readability. Link: https://lkml.kernel.org/r/20240820042254.99115-2-thorsten.blum@toblux.com Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Cc: Dave Chinner <david@fromorbit.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-20 06:22:55 +02:00
mm: shrinkers: add scan interface for shrinker debugfs Add a scan interface which allows to trigger scanning of a particular shrinker and specify memcg and numa node. It's useful for testing, debugging and profiling of a specific scan_objects() callback. Unlike alternatives (creating a real memory pressure and dropping caches via /proc/sys/vm/drop_caches) this interface allows to interact with only one shrinker at once. Also, if a shrinker is misreporting the number of objects (as some do), it doesn't affect scanning. [roman.gushchin@linux.dev: improve typing, fix arg count checking] Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon [akpm@linux-foundation.org: fix arg count checking] Link: https://lkml.kernel.org/r/20220601032227.4076670-7-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:27 -07:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix debugfs file permissions The permissions for the files here are swapped as "count" is read-only and "scan" is write-only. While this doesn't really matter as these permissions don't stop the files being opened for reading/writing as appropriate, they are shown by "ls -l" and are confusing. Link: https://lkml.kernel.org/r/20230418101906.3131303-1-john@metanate.com Signed-off-by: John Keeping <john@metanate.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 11:19:05 +01:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix debugfs file permissions The permissions for the files here are swapped as "count" is read-only and "scan" is write-only. While this doesn't really matter as these permissions don't stop the files being opened for reading/writing as appropriate, they are shown by "ls -l" and are confusing. Link: https://lkml.kernel.org/r/20230418101906.3131303-1-john@metanate.com Signed-off-by: John Keeping <john@metanate.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 11:19:05 +01:00
mm: shrinkers: add scan interface for shrinker debugfs Add a scan interface which allows to trigger scanning of a particular shrinker and specify memcg and numa node. It's useful for testing, debugging and profiling of a specific scan_objects() callback. Unlike alternatives (creating a real memory pressure and dropping caches via /proc/sys/vm/drop_caches) this interface allows to interact with only one shrinker at once. Also, if a shrinker is misreporting the number of objects (as some do), it doesn't affect scanning. [roman.gushchin@linux.dev: improve typing, fix arg count checking] Link: https://lkml.kernel.org/r/YpgKttTowT22mKPQ@carbon [akpm@linux-foundation.org: fix arg count checking] Link: https://lkml.kernel.org/r/20220601032227.4076670-7-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:27 -07:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
saner replacement for debugfs_rename() Existing primitive has several problems: 1) calling conventions are clumsy - it returns a dentry reference that is either identical to its second argument or is an ERR_PTR(-E...); in both cases no refcount changes happen. Inconvenient for users and bug-prone; it would be better to have it return 0 on success and -E... on failure. 2) it allows cross-directory moves; however, no such caller have ever materialized and considering the way debugfs is used, it's unlikely to happen in the future. What's more, any such caller would have fun issues to deal with wrt interplay with recursive removal. It also makes the calling conventions clumsier... 3) tautological rename fails; the callers have no race-free way to deal with that. 4) new name must have been formed by the caller; quite a few callers have it done by sprintf/kasprintf/etc., ending up with considerable boilerplate. Proposed replacement: int debugfs_change_name(dentry, fmt, ...). All callers convert to that easily, and it's simpler internally. IMO debugfs_rename() should go; if we ever get a real-world use case for cross-directory moves in debugfs, we can always look into the right way to handle that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/r/20250112080705.141166-21-viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-12 08:07:05 +00:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: provide shrinkers with names Currently shrinkers are anonymous objects. For debugging purposes they can be identified by count/scan function names, but it's not always useful: e.g. for superblock's shrinkers it's nice to have at least an idea of to which superblock the shrinker belongs. This commit adds names to shrinkers. register_shrinker() and prealloc_shrinker() functions are extended to take a format and arguments to master a name. In some cases it's not possible to determine a good name at the time when a shrinker is allocated. For such cases shrinker_debugfs_rename() is provided. The expected format is: <subsystem>-<shrinker_type>[:<instance>]-<id> For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair. After this change the shrinker debugfs directory looks like: $ cd /sys/kernel/debug/shrinker/ $ ls dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42 mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43 mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44 rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49 sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13 sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36 sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19 sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10 sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9 sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37 sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38 sb-dax-11 sb-proc-45 sb-tmpfs-35 sb-debugfs-7 sb-proc-46 sb-tmpfs-40 [roman.gushchin@linux.dev: fix build warnings] Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle Reported-by: kernel test robot <lkp@intel.com> Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:24 -07:00
mm: shrinkers: fix race condition on debugfs cleanup When something registers and unregisters many shrinkers, such as: for x in $(seq 10000); do unshare -Ui true; done Sometimes the following error is printed to the kernel log: debugfs: Directory '...' with parent 'shrinker' already present! This occurs since commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") / v6.2: Since the call to `debugfs_remove_recursive` was moved outside the `shrinker_rwsem`/`shrinker_mutex` lock, but the call to `ida_free` stayed inside, a newly registered shrinker can be re-assigned that ID and attempt to create the debugfs directory before the directory from the previous shrinker has been removed. The locking changes in commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless") made the race condition more likely, though it existed before then. Commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") could be reverted since the issue is addressed should no longer occur since the count and scan operations are lockless since commit 20cd1892fcc3 ("mm: shrinkers: make count and scan in shrinker debugfs lockless"). However, since this is a contended lock, prefer instead moving `ida_free` outside the lock to avoid the race. Link: https://lkml.kernel.org/r/20230503013232.299211-1-joanbrugueram@gmail.com Fixes: badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-03 01:32:32 +00:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix deadlock in shrinker debugfs The debugfs_remove_recursive() is invoked by unregister_shrinker(), which is holding the write lock of shrinker_rwsem. It will waits for the handler of debugfs file complete. The handler also needs to hold the read lock of shrinker_rwsem to do something. So it may cause the following deadlock: CPU0 CPU1 debugfs_file_get() shrinker_debugfs_count_show()/shrinker_debugfs_scan_write() unregister_shrinker() --> down_write(&shrinker_rwsem); debugfs_remove_recursive() // wait for (A) --> wait_for_completion(); // wait for (B) --> down_read_killable(&shrinker_rwsem) debugfs_file_put() -- (A) up_write() -- (B) The down_read_killable() can be killed, so that the above deadlock can be recovered. But it still requires an extra kill action, otherwise it will block all subsequent shrinker-related operations, so it's better to fix it. [akpm@linux-foundation.org: fix CONFIG_SHRINKER_DEBUG=n stub] Link: https://lkml.kernel.org/r/20230202105612.64641-1-zhengqi.arch@bytedance.com Fixes: 5035ebc644ae ("mm: shrinkers: introduce debugfs interface for memory shrinkers") Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 18:56:12 +08:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix race condition on debugfs cleanup When something registers and unregisters many shrinkers, such as: for x in $(seq 10000); do unshare -Ui true; done Sometimes the following error is printed to the kernel log: debugfs: Directory '...' with parent 'shrinker' already present! This occurs since commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") / v6.2: Since the call to `debugfs_remove_recursive` was moved outside the `shrinker_rwsem`/`shrinker_mutex` lock, but the call to `ida_free` stayed inside, a newly registered shrinker can be re-assigned that ID and attempt to create the debugfs directory before the directory from the previous shrinker has been removed. The locking changes in commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless") made the race condition more likely, though it existed before then. Commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") could be reverted since the issue is addressed should no longer occur since the count and scan operations are lockless since commit 20cd1892fcc3 ("mm: shrinkers: make count and scan in shrinker debugfs lockless"). However, since this is a contended lock, prefer instead moving `ida_free` outside the lock to avoid the race. Link: https://lkml.kernel.org/r/20230503013232.299211-1-joanbrugueram@gmail.com Fixes: badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-03 01:32:32 +00:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix deadlock in shrinker debugfs The debugfs_remove_recursive() is invoked by unregister_shrinker(), which is holding the write lock of shrinker_rwsem. It will waits for the handler of debugfs file complete. The handler also needs to hold the read lock of shrinker_rwsem to do something. So it may cause the following deadlock: CPU0 CPU1 debugfs_file_get() shrinker_debugfs_count_show()/shrinker_debugfs_scan_write() unregister_shrinker() --> down_write(&shrinker_rwsem); debugfs_remove_recursive() // wait for (A) --> wait_for_completion(); // wait for (B) --> down_read_killable(&shrinker_rwsem) debugfs_file_put() -- (A) up_write() -- (B) The down_read_killable() can be killed, so that the above deadlock can be recovered. But it still requires an extra kill action, otherwise it will block all subsequent shrinker-related operations, so it's better to fix it. [akpm@linux-foundation.org: fix CONFIG_SHRINKER_DEBUG=n stub] Link: https://lkml.kernel.org/r/20230202105612.64641-1-zhengqi.arch@bytedance.com Fixes: 5035ebc644ae ("mm: shrinkers: introduce debugfs interface for memory shrinkers") Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 18:56:12 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinkers: fix race condition on debugfs cleanup When something registers and unregisters many shrinkers, such as: for x in $(seq 10000); do unshare -Ui true; done Sometimes the following error is printed to the kernel log: debugfs: Directory '...' with parent 'shrinker' already present! This occurs since commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") / v6.2: Since the call to `debugfs_remove_recursive` was moved outside the `shrinker_rwsem`/`shrinker_mutex` lock, but the call to `ida_free` stayed inside, a newly registered shrinker can be re-assigned that ID and attempt to create the debugfs directory before the directory from the previous shrinker has been removed. The locking changes in commit f95bdb700bc6 ("mm: vmscan: make global slab shrink lockless") made the race condition more likely, though it existed before then. Commit badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") could be reverted since the issue is addressed should no longer occur since the count and scan operations are lockless since commit 20cd1892fcc3 ("mm: shrinkers: make count and scan in shrinker debugfs lockless"). However, since this is a contended lock, prefer instead moving `ida_free` outside the lock to avoid the race. Link: https://lkml.kernel.org/r/20230503013232.299211-1-joanbrugueram@gmail.com Fixes: badc28d4924b ("mm: shrinkers: fix deadlock in shrinker debugfs") Signed-off-by: Joan Bruguera Micó <joanbrugueram@gmail.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-03 01:32:32 +00:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00
mm: shrinker: convert shrinker_rwsem to mutex Now there are no readers of shrinker_rwsem, so we can simply replace it with mutex lock. [akpm@linux-foundation.org: update the fix to alloc_shrinker_info()] Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Abhinav Kumar <quic_abhinavk@quicinc.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Carlos Llamas <cmllamas@google.com> Cc: Chandan Babu R <chandan.babu@oracle.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christian Koenig <christian.koenig@amd.com> Cc: Chuck Lever <cel@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: Dai Ngo <Dai.Ngo@oracle.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Airlie <airlied@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Sterba <dsterba@suse.com> Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Cc: Gao Xiang <hsiangkao@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Rui <ray.huang@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jeffle Xu <jefflexu@linux.alibaba.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Kirill Tkhai <tkhai@ya.ru> Cc: Marijn Suijten <marijn.suijten@somainline.org> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Mike Snitzer <snitzer@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Olga Kornievskaia <kolga@netapp.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Clark <robdclark@gmail.com> Cc: Rob Herring <robh@kernel.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sean Paul <sean@poorly.run> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Song Liu <song@kernel.org> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Tom Talpey <tom@talpey.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Yue Hu <huyue2@coolpad.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-11 17:44:44 +08:00
mm: shrinkers: introduce debugfs interface for memory shrinkers This commit introduces the /sys/kernel/debug/shrinker debugfs interface which provides an ability to observe the state of individual kernel memory shrinkers. Because the feature adds some memory overhead (which shouldn't be large unless there is a huge amount of registered shrinkers), it's guarded by a config option (enabled by default). This commit introduces the "count" interface for each shrinker registered in the system. The output is in the following format: <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... <cgroup inode id> <nr of objects on node 0> <nr of objects on node 1>... ... To reduce the size of output on machines with many thousands cgroups, if the total number of objects on all nodes is 0, the line is omitted. If the shrinker is not memcg-aware or CONFIG_MEMCG is off, 0 is printed as cgroup inode id. If the shrinker is not numa-aware, 0's are printed for all nodes except the first one. This commit gives debugfs entries simple numeric names, which are not very convenient. The following commit in the series will provide shrinkers with more meaningful names. [akpm@linux-foundation.org: remove WARN_ON_ONCE(), per Roman] Reported-by: syzbot+300d27c79fe6d4cbcc39@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/20220601032227.4076670-3-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hillf Danton <hdanton@sina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-31 20:22:23 -07:00