kernel/linux
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-11-13 07:31:07 +00:00
Code Issues Releases Packages Activity
linux/lib/plist.c

299 lines
7 KiB
Raw Normal View History

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 10 Based on 1 normalized pattern(s): licensed under the fsf s gnu public license v2 or later extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 2 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190519154041.526489261@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-19 15:51:40 +02:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
bug.h: add include of it to various implicit C users With bug.h currently living right in linux/kernel.h there are files that use BUG_ON and friends but are not including the header explicitly. Fix them up so we can remove the presence in kernel.h file. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-01-20 18:35:53 -05:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
lib/plist: rename DEBUG_PI_LIST to DEBUG_PLIST This is a lot more appropriate than PI_LIST, which in the kernel one would assume that it has to do with priority-inheritance; which is not -- furthermore futexes make use of plists so this can be even more confusing, albeit the debug nature of the config option. Link: http://lkml.kernel.org/r/20190317185434.1626-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 15:42:46 -07:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
Use WARN() in lib/ Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. In addition, one of the if() clauses collapes into the WARN() entirely now. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 19:45:39 -07:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
lib/plist.c: enforce memory ordering in plist_check_list There exists an iteration over a plist in plist_check_list(), and memory dependency exists between variables "prev", "next" and "prev->next". As plist is used in the scheduling subsystem, we should guarantee the memory ordering between multiple processors. Using macro "WRITE_ONCE()" can help us to ensure the memory ordering as it was stated in "Documentation/memory-barriers.txt". Link: https://lkml.kernel.org/r/20240526140139.17220-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-26 22:01:39 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
lib/plist.c: avoid worst case scenario in plist_add Worst case scenario of plist_add() happens when the priority of the inserted plist_node is going to be the largest after the insertion is done. The cost is going to be more significant when the original plist is longer, because the iterator is going to traverse the whole plist to find the correct position to insert the new node. The situation can be avoided by using a reverse iterator at the same time, doing so the maximum possible number of iteration is going to shrink from N to N/2. The proposed change of plist_add pasts the test in lib/plist.c to validate its correctness, also add the worst case scenario test for plist_add() in plist_test(). The worst case test are tested with the size of test_data and test_node growing from 200 to 1000. The result are showned in the following table, in which we can observed that the proposed change of plist_add performs better than the original version, and the difference between these two implementations are more significant with the size of N growing. The random case test [1], and best case test [2] are also provided, with result showing the proposed change performs slightly better in random case test while the original implementation performs slightly better in best case test, while the difference in both test are minor, we can see them as even in those two situations. ----------------------------------------------------------- | Test size | 200 | 400 | 600 | 800 | 1000 | ----------------------------------------------------------- | new_plist_add | 140911| 548681| 1220512| 2048493| 3763755| ----------------------------------------------------------- | old_plist_add | 188198| 774222| 1643547| 3008929| 4947435| ----------------------------------------------------------- Link: https://lkml.kernel.org/r/20240614154603.65203-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-14 23:46:03 +08:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
lib/plist.c: avoid worst case scenario in plist_add Worst case scenario of plist_add() happens when the priority of the inserted plist_node is going to be the largest after the insertion is done. The cost is going to be more significant when the original plist is longer, because the iterator is going to traverse the whole plist to find the correct position to insert the new node. The situation can be avoided by using a reverse iterator at the same time, doing so the maximum possible number of iteration is going to shrink from N to N/2. The proposed change of plist_add pasts the test in lib/plist.c to validate its correctness, also add the worst case scenario test for plist_add() in plist_test(). The worst case test are tested with the size of test_data and test_node growing from 200 to 1000. The result are showned in the following table, in which we can observed that the proposed change of plist_add performs better than the original version, and the difference between these two implementations are more significant with the size of N growing. The random case test [1], and best case test [2] are also provided, with result showing the proposed change performs slightly better in random case test while the original implementation performs slightly better in best case test, while the difference in both test are minor, we can see them as even in those two situations. ----------------------------------------------------------- | Test size | 200 | 400 | 600 | 800 | 1000 | ----------------------------------------------------------- | new_plist_add | 140911| 548681| 1220512| 2048493| 3763755| ----------------------------------------------------------- | old_plist_add | 188198| 774222| 1643547| 3008929| 4947435| ----------------------------------------------------------- Link: https://lkml.kernel.org/r/20240614154603.65203-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-14 23:46:03 +08:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
lib/plist.c: avoid worst case scenario in plist_add Worst case scenario of plist_add() happens when the priority of the inserted plist_node is going to be the largest after the insertion is done. The cost is going to be more significant when the original plist is longer, because the iterator is going to traverse the whole plist to find the correct position to insert the new node. The situation can be avoided by using a reverse iterator at the same time, doing so the maximum possible number of iteration is going to shrink from N to N/2. The proposed change of plist_add pasts the test in lib/plist.c to validate its correctness, also add the worst case scenario test for plist_add() in plist_test(). The worst case test are tested with the size of test_data and test_node growing from 200 to 1000. The result are showned in the following table, in which we can observed that the proposed change of plist_add performs better than the original version, and the difference between these two implementations are more significant with the size of N growing. The random case test [1], and best case test [2] are also provided, with result showing the proposed change performs slightly better in random case test while the original implementation performs slightly better in best case test, while the difference in both test are minor, we can see them as even in those two situations. ----------------------------------------------------------- | Test size | 200 | 400 | 600 | 800 | 1000 | ----------------------------------------------------------- | new_plist_add | 140911| 548681| 1220512| 2048493| 3763755| ----------------------------------------------------------- | old_plist_add | 188198| 774222| 1643547| 3008929| 4947435| ----------------------------------------------------------- Link: https://lkml.kernel.org/r/20240614154603.65203-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-14 23:46:03 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
lib/plist.c: avoid worst case scenario in plist_add Worst case scenario of plist_add() happens when the priority of the inserted plist_node is going to be the largest after the insertion is done. The cost is going to be more significant when the original plist is longer, because the iterator is going to traverse the whole plist to find the correct position to insert the new node. The situation can be avoided by using a reverse iterator at the same time, doing so the maximum possible number of iteration is going to shrink from N to N/2. The proposed change of plist_add pasts the test in lib/plist.c to validate its correctness, also add the worst case scenario test for plist_add() in plist_test(). The worst case test are tested with the size of test_data and test_node growing from 200 to 1000. The result are showned in the following table, in which we can observed that the proposed change of plist_add performs better than the original version, and the difference between these two implementations are more significant with the size of N growing. The random case test [1], and best case test [2] are also provided, with result showing the proposed change performs slightly better in random case test while the original implementation performs slightly better in best case test, while the difference in both test are minor, we can see them as even in those two situations. ----------------------------------------------------------- | Test size | 200 | 400 | 600 | 800 | 1000 | ----------------------------------------------------------- | new_plist_add | 140911| 548681| 1220512| 2048493| 3763755| ----------------------------------------------------------- | old_plist_add | 188198| 774222| 1643547| 3008929| 4947435| ----------------------------------------------------------- Link: https://lkml.kernel.org/r/20240614154603.65203-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-14 23:46:03 +08:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Shrink struct plist_head struct plist_head is used in struct task_struct as well as struct rtmutex. If we can make it smaller, it will also make these structures smaller as well. The field prio_list in struct plist_head is seldom used and we can get its information from the plist_nodes. Removing this field will decrease the size of plist_head by half. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107982.9090700@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:14 +08:00
[PATCH] pi-futex: add plist implementation Add the priority-sorted list (plist) implementation. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27 02:54:51 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
lib/plist: add plist_requeue Add plist_requeue(), which moves the specified plist_node after all other same-priority plist_nodes in the list. This is essentially an optimized plist_del() followed by plist_add(). This is needed by swap, which (with the next patch in this set) uses a plist of available swap devices. When a swap device (either a swap partition or swap file) are added to the system with swapon(), the device is added to a plist, ordered by the swap device's priority. When swap needs to allocate a page from one of the swap devices, it takes the page from the first swap device on the plist, which is the highest priority swap device. The swap device is left in the plist until all its pages are used, and then removed from the plist when it becomes full. However, as described in man 2 swapon, swap must allocate pages from swap devices with the same priority in round-robin order; to do this, on each swap page allocation, swap uses a page from the first swap device in the plist, and then calls plist_requeue() to move that swap device entry to after any other same-priority swap devices. The next swap page allocation will again use a page from the first swap device in the plist and requeue it, and so on, resulting in round-robin usage of equal-priority swap devices. Also add plist_test_requeue() test function, for use by plist_test() to test plist_requeue() function. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:09:57 -07:00
lib/plist: rename DEBUG_PI_LIST to DEBUG_PLIST This is a lot more appropriate than PI_LIST, which in the kernel one would assume that it has to do with priority-inheritance; which is not -- furthermore futexes make use of plists so this can be even more confusing, albeit the debug nature of the config option. Link: http://lkml.kernel.org/r/20190317185434.1626-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-05-14 15:42:46 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-01 16:36:40 +01:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
lib/plist: add plist_requeue Add plist_requeue(), which moves the specified plist_node after all other same-priority plist_nodes in the list. This is essentially an optimized plist_del() followed by plist_add(). This is needed by swap, which (with the next patch in this set) uses a plist of available swap devices. When a swap device (either a swap partition or swap file) are added to the system with swapon(), the device is added to a plist, ordered by the swap device's priority. When swap needs to allocate a page from one of the swap devices, it takes the page from the first swap device on the plist, which is the highest priority swap device. The swap device is left in the plist until all its pages are used, and then removed from the plist when it becomes full. However, as described in man 2 swapon, swap must allocate pages from swap devices with the same priority in round-robin order; to do this, on each swap page allocation, swap uses a page from the first swap device in the plist, and then calls plist_requeue() to move that swap device entry to after any other same-priority swap devices. The next swap page allocation will again use a page from the first swap device in the plist and requeue it, and so on, resulting in round-robin usage of equal-priority swap devices. Also add plist_test_requeue() test function, for use by plist_test() to test plist_requeue() function. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:09:57 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
lib/plist.c: replace pr_debug with printk in plist_test() Replace pr_debug() in lib/plist.c test function plist_test() with printk(KERN_DEBUG ...). Without DEBUG defined, pr_debug() is complied out, but the entire plist_test() function is already inside CONFIG_DEBUG_PI_LIST, so printk should just be used directly. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:11:49 -07:00
plist: Remove the need to supply locks to plist heads This was legacy code brought over from the RT tree and is no longer necessary. Signed-off-by: Dima Zavin <dima@android.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Walker <dwalker@codeaurora.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Link: http://lkml.kernel.org/r/1310084879-10351-2-git-send-email-dima@android.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-07-07 17:27:59 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
lib/plist: add plist_requeue Add plist_requeue(), which moves the specified plist_node after all other same-priority plist_nodes in the list. This is essentially an optimized plist_del() followed by plist_add(). This is needed by swap, which (with the next patch in this set) uses a plist of available swap devices. When a swap device (either a swap partition or swap file) are added to the system with swapon(), the device is added to a plist, ordered by the swap device's priority. When swap needs to allocate a page from one of the swap devices, it takes the page from the first swap device on the plist, which is the highest priority swap device. The swap device is left in the plist until all its pages are used, and then removed from the plist when it becomes full. However, as described in man 2 swapon, swap must allocate pages from swap devices with the same priority in round-robin order; to do this, on each swap page allocation, swap uses a page from the first swap device in the plist, and then calls plist_requeue() to move that swap device entry to after any other same-priority swap devices. The next swap page allocation will again use a page from the first swap device in the plist and requeue it, and so on, resulting in round-robin usage of equal-priority swap devices. Also add plist_test_requeue() test function, for use by plist_test() to test plist_requeue() function. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Shaohua Li <shli@fusionio.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Cc: Weijie Yang <weijieut@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Bob Liu <bob.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:09:57 -07:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00
lib/plist.c: replace pr_debug with printk in plist_test() Replace pr_debug() in lib/plist.c test function plist_test() with printk(KERN_DEBUG ...). Without DEBUG defined, pr_debug() is complied out, but the entire plist_test() function is already inside CONFIG_DEBUG_PI_LIST, so printk should just be used directly. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:11:49 -07:00
lib/plist.c: avoid worst case scenario in plist_add Worst case scenario of plist_add() happens when the priority of the inserted plist_node is going to be the largest after the insertion is done. The cost is going to be more significant when the original plist is longer, because the iterator is going to traverse the whole plist to find the correct position to insert the new node. The situation can be avoided by using a reverse iterator at the same time, doing so the maximum possible number of iteration is going to shrink from N to N/2. The proposed change of plist_add pasts the test in lib/plist.c to validate its correctness, also add the worst case scenario test for plist_add() in plist_test(). The worst case test are tested with the size of test_data and test_node growing from 200 to 1000. The result are showned in the following table, in which we can observed that the proposed change of plist_add performs better than the original version, and the difference between these two implementations are more significant with the size of N growing. The random case test [1], and best case test [2] are also provided, with result showing the proposed change performs slightly better in random case test while the original implementation performs slightly better in best case test, while the difference in both test are minor, we can see them as even in those two situations. ----------------------------------------------------------- | Test size | 200 | 400 | 600 | 800 | 1000 | ----------------------------------------------------------- | new_plist_add | 140911| 548681| 1220512| 2048493| 3763755| ----------------------------------------------------------- | old_plist_add | 188198| 774222| 1643547| 3008929| 4947435| ----------------------------------------------------------- Link: https://lkml.kernel.org/r/20240614154603.65203-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-14 23:46:03 +08:00
plist: Add priority list test Add test code for checking plist when the kernel is booting. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4D107986.1010302@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-12-21 17:55:18 +08:00