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linux/include/trace/events/writeback.h

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writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: show writeback reason with __print_symbolic This makes the binary trace understandable by trace-cmd. CC: Dave Chinner <david@fromorbit.com> CC: Curt Wohlgemuth <curtw@google.com> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-12-08 16:53:54 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: add more tracepoints Add tracepoints for page dirtying, writeback_single_inode start, inode dirtying and writeback. For the latter two inode events, a pair of events are defined to denote start and end of the operations (the starting one has _start suffix and the one w/o suffix happens after the operation is complete). These inode ops are FS specific and can be non-trivial and having enclosing tracepoints is useful for external tracers. This is part of tracepoint additions to improve visiblity into dirtying / writeback operations for io tracer and userland. v2: writeback_dirty_inode[_start] TPs may be called for files on pseudo FSes w/ unregistered bdi. Check whether bdi->dev is %NULL before dereferencing. v3: buffer dirtying moved to a block TP. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-01-11 13:06:37 -08:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue When a SD card is hot removed without umount, del_gendisk() will call bdi_unregister() without destroying/freeing it. This leaves the bdi in the bdi->dev = NULL, bdi->wb.task = NULL, bdi->bdi_list removed state. When sync(2) gets the bdi before bdi_unregister() and calls bdi_queue_work() after the unregister, trace_writeback_queue will be dereferencing the NULL bdi->dev. Fix it with a simple test for NULL. LKML-reference: http://lkml.org/lkml/2012/1/18/346 Cc: stable@kernel.org Reported-by: Rabin Vincent <rabin@rab.in> Tested-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2012-02-04 20:54:03 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: show writeback reason with __print_symbolic This makes the binary trace understandable by trace-cmd. CC: Dave Chinner <david@fromorbit.com> CC: Curt Wohlgemuth <curtw@google.com> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-12-08 16:53:54 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: make writeback_control.nr_to_write straight Pass struct wb_writeback_work all the way down to writeback_sb_inodes(), and initialize the struct writeback_control there. struct writeback_control is basically designed to control writeback of a single file, but we keep abuse it for writing multiple files in writeback_sb_inodes() and its callers. It immediately clean things up, e.g. suddenly wbc.nr_to_write vs work->nr_pages starts to make sense, and instead of saving and restoring pages_skipped in writeback_sb_inodes it can always start with a clean zero value. It also makes a neat IO pattern change: large dirty files are now written in the full 4MB writeback chunk size, rather than whatever remained quota in wbc->nr_to_write. Acked-by: Jan Kara <jack@suse.cz> Proposed-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-05-04 19:54:37 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: trace wakeup event for background writeback This tracks when balance_dirty_pages() tries to wakeup the flusher thread for background writeback (if it was not started already). Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Engelhardt <jengelh@medozas.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 15:45:46 -08:00
writeback: add new tracepoints Add 2 new trace points to the periodic write-back wake up case, just like we do in the 'bdi_queue_work()' function. Namely, introduce: 1. trace_writeback_wake_thread(bdi) 2. trace_writeback_wake_forker_thread(bdi) The first event is triggered every time we wake up a bdi thread to start periodic background write-out. The second event is triggered only when the bdi thread does not exist and should be created by the forker thread. This patch was suggested by Dave Chinner and Christoph Hellwig. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-25 14:29:24 +03:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00
writeback: Add tracing to balance_dirty_pages Tracing high level background writeback events is good, but it doesn't give the entire picture. Add visibility into write throttling to catch IO dispatched by foreground throttling of processing dirtying lots of pages. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:07 +10:00
writeback: make writeback_control.nr_to_write straight Pass struct wb_writeback_work all the way down to writeback_sb_inodes(), and initialize the struct writeback_control there. struct writeback_control is basically designed to control writeback of a single file, but we keep abuse it for writing multiple files in writeback_sb_inodes() and its callers. It immediately clean things up, e.g. suddenly wbc.nr_to_write vs work->nr_pages starts to make sense, and instead of saving and restoring pages_skipped in writeback_sb_inodes it can always start with a clean zero value. It also makes a neat IO pattern change: large dirty files are now written in the full 4MB writeback chunk size, rather than whatever remained quota in wbc->nr_to_write. Acked-by: Jan Kara <jack@suse.cz> Proposed-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-05-04 19:54:37 -06:00
writeback: Add tracing to balance_dirty_pages Tracing high level background writeback events is good, but it doesn't give the entire picture. Add visibility into write throttling to catch IO dispatched by foreground throttling of processing dirtying lots of pages. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:07 +10:00
writeback: Add tracing to write_cache_pages Add a trace event to the ->writepage loop in write_cache_pages to give visibility into how the ->writepage call is changing variables within the writeback control structure. Of most interest is how wbc->nr_to_write changes from call to call, especially with filesystems that write multiple pages in ->writepage. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:08 +10:00
writeback: Add tracing to balance_dirty_pages Tracing high level background writeback events is good, but it doesn't give the entire picture. Add visibility into write throttling to catch IO dispatched by foreground throttling of processing dirtying lots of pages. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:07 +10:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: send work item to queue_io, move_expired_inodes Instead of sending ->older_than_this to queue_io() and move_expired_inodes(), send the entire wb_writeback_work structure. There are other fields of a work item that are useful in these routines and in tracepoints. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:51:56 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: send work item to queue_io, move_expired_inodes Instead of sending ->older_than_this to queue_io() and move_expired_inodes(), send the entire wb_writeback_work structure. There are other fields of a work item that are useful in these routines and in tracepoints. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:51:56 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: send work item to queue_io, move_expired_inodes Instead of sending ->older_than_this to queue_io() and move_expired_inodes(), send the entire wb_writeback_work structure. There are other fields of a work item that are useful in these routines and in tracepoints. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:51:56 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: Add a 'reason' to wb_writeback_work This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-10-07 21:54:10 -06:00
writeback: show writeback reason with __print_symbolic This makes the binary trace understandable by trace-cmd. CC: Dave Chinner <david@fromorbit.com> CC: Curt Wohlgemuth <curtw@google.com> CC: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-12-08 16:53:54 -06:00
writeback: trace event writeback_queue_io Note that it adds a little overheads to account the moved/enqueued inodes from b_dirty to b_io. The "moved" accounting may be later used to limit the number of inodes that can be moved in one shot, in order to keep spinlock hold time under control. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-04-23 12:27:27 -06:00
writeback: trace global_dirty_state Add trace event balance_dirty_state for showing the global dirty page counts and thresholds at each global_dirty_limits() invocation. This will cover the callers throttle_vm_writeout(), over_bground_thresh() and each balance_dirty_pages() loop. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-06 22:34:29 -06:00
writeback: trace event bdi_dirty_ratelimit It helps understand how various throttle bandwidths are updated. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-03-02 17:22:49 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: dirty ratelimit - think time compensation Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-11 19:25:42 -06:00
writeback: trace event balance_dirty_pages Useful for analyzing the dynamics of the throttling algorithms and debugging user reported problems. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-08-29 23:33:20 -06:00
writeback: Move requeueing when I_SYNC set to writeback_sb_inodes() When writeback_single_inode() is called on inode which has I_SYNC already set while doing WB_SYNC_NONE, inode is moved to b_more_io list. However this makes sense only if the caller is flusher thread. For other callers of writeback_single_inode() it doesn't really make sense and may be even wrong - flusher thread may be doing WB_SYNC_ALL writeback in parallel. So we move requeueing from writeback_single_inode() to writeback_sb_inodes(). Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2012-05-03 14:47:56 +02:00
writeback: account for time spent congestion_waited There is strong evidence to indicate a lot of time is being spent in congestion_wait(), some of it unnecessarily. This patch adds a tracepoint for congestion_wait to record when congestion_wait() was called, how long the timeout was for and how long it actually slept. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 14:21:41 -07:00
writeback: do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone If congestion_wait() is called with no BDI congested, the caller will sleep for the full timeout and this may be an unnecessary sleep. This patch adds a wait_iff_congested() that checks congestion and only sleeps if a BDI is congested else, it calls cond_resched() to ensure the caller is not hogging the CPU longer than its quota but otherwise will not sleep. This is aimed at reducing some of the major desktop stalls reported during IO. For example, while kswapd is operating, it calls congestion_wait() but it could just have been reclaiming clean page cache pages with no congestion. Without this patch, it would sleep for a full timeout but after this patch, it'll just call schedule() if it has been on the CPU too long. Similar logic applies to direct reclaimers that are not making enough progress. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 14:21:45 -07:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: show raw dirtied_when in trace writeback_single_inode Save inode->dirtied_when in the raw trace output for reliable scripting, and to also show in formatted output the relative age in seconds for easy human reading. CC: Jan Kara <jack@suse.cz> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-08-29 09:52:23 -06:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: fix NULL bdi->dev in trace writeback_single_inode bdi_prune_sb() resets sb->s_bdi to default_backing_dev_info when the tearing down the original bdi. Fix trace_writeback_single_inode to use sb->s_bdi=default_backing_dev_info rather than bdi->dev=NULL for a teared down bdi. Cc: <stable@kernel.org> Reported-by: Rabin Vincent <rabin@rab.in> Tested-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2012-01-17 11:18:56 -06:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: show raw dirtied_when in trace writeback_single_inode Save inode->dirtied_when in the raw trace output for reliable scripting, and to also show in formatted output the relative age in seconds for easy human reading. CC: Jan Kara <jack@suse.cz> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-08-29 09:52:23 -06:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: show raw dirtied_when in trace writeback_single_inode Save inode->dirtied_when in the raw trace output for reliable scripting, and to also show in formatted output the relative age in seconds for easy human reading. CC: Jan Kara <jack@suse.cz> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-08-29 09:52:23 -06:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: show raw dirtied_when in trace writeback_single_inode Save inode->dirtied_when in the raw trace output for reliable scripting, and to also show in formatted output the relative age in seconds for easy human reading. CC: Jan Kara <jack@suse.cz> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-08-29 09:52:23 -06:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: add more tracepoints Add tracepoints for page dirtying, writeback_single_inode start, inode dirtying and writeback. For the latter two inode events, a pair of events are defined to denote start and end of the operations (the starting one has _start suffix and the one w/o suffix happens after the operation is complete). These inode ops are FS specific and can be non-trivial and having enclosing tracepoints is useful for external tracers. This is part of tracepoint additions to improve visiblity into dirtying / writeback operations for io tracer and userland. v2: writeback_dirty_inode[_start] TPs may be called for files on pseudo FSes w/ unregistered bdi. Check whether bdi->dev is %NULL before dereferencing. v3: buffer dirtying moved to a block TP. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-01-11 13:06:37 -08:00
writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2010-12-01 17:33:37 -06:00
writeback: Initial tracing support Trace queue/sched/exec parts of the writeback loop. This provides insight into when and why flusher threads are scheduled to run. e.g a sync invocation leaves traces like: sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0 This also lays the foundation for adding more writeback tracing to provide deeper insight into the whole writeback path. The original tracing code is from Jens Axboe, though this version is a rewrite as a result of the code being traced changing significantly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-07-07 13:24:06 +10:00