- 19 6月, 2015 8 次提交
-
-
由 Wanpeng Li 提交于
This patch adds a check that prevents futile attempts to move DL tasks to a CPU with active tasks of equal or earlier deadline. The same behavior as commit 80e3d87b ("sched/rt: Reduce rq lock contention by eliminating locking of non-feasible target") for rt class. Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431496867-4194-3-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Wanpeng Li 提交于
It's a bootstrap function, make init_sched_dl_class() __init. Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431496867-4194-2-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Wanpeng Li 提交于
pull_dl_task() uses pick_next_earliest_dl_task() to select a migration candidate; this is sub-optimal since the next earliest task -- as per the regular runqueue -- might not be migratable at all. This could result in iterating the entire runqueue looking for a task. Instead iterate the pushable queue -- this queue only contains tasks that have at least 2 cpus set in their cpus_allowed mask. Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> [ Improved the changelog. ] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431496867-4194-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Peter Zijlstra 提交于
Avoid touching the curr->preempt_notifier cacheline when not needed. Provides a small improvement on pipe-bench: taskset 01 perf stat --repeat 10 -- perf bench sched pipe before: Performance counter stats for 'perf bench sched pipe' (10 runs): 12385.016204 task-clock (msec) # 1.001 CPUs utilized ( +- 0.34% ) 2,000,023 context-switches # 0.161 M/sec ( +- 0.00% ) 0 cpu-migrations # 0.000 K/sec 175 page-faults # 0.014 K/sec ( +- 0.26% ) 41,376,162,250 cycles # 3.341 GHz ( +- 0.11% ) 17,389,139,321 stalled-cycles-frontend # 42.03% frontend cycles idle ( +- 0.25% ) <not supported> stalled-cycles-backend 68,788,588,003 instructions # 1.66 insns per cycle # 0.25 stalled cycles per insn ( +- 0.02% ) 13,449,387,620 branches # 1085.940 M/sec ( +- 0.02% ) 20,880,690 branch-misses # 0.16% of all branches ( +- 0.98% ) 12.372646094 seconds time elapsed ( +- 0.34% ) after: Performance counter stats for 'perf bench sched pipe' (10 runs): 12180.936528 task-clock (msec) # 1.001 CPUs utilized ( +- 0.33% ) 2,000,077 context-switches # 0.164 M/sec ( +- 0.00% ) 0 cpu-migrations # 0.000 K/sec 174 page-faults # 0.014 K/sec ( +- 0.27% ) 40,691,545,577 cycles # 3.341 GHz ( +- 0.06% ) 16,446,333,371 stalled-cycles-frontend # 40.42% frontend cycles idle ( +- 0.18% ) <not supported> stalled-cycles-backend 68,570,100,387 instructions # 1.69 insns per cycle # 0.24 stalled cycles per insn ( +- 0.01% ) 13,389,740,014 branches # 1099.237 M/sec ( +- 0.01% ) 20,175,440 branch-misses # 0.15% of all branches ( +- 0.52% ) 12.169253010 seconds time elapsed ( +- 0.33% ) Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Mathieu Desnoyers 提交于
preempt_notifier_unregister() documents: "This is safe to call from within a preemption notifier." However, both fire_sched_in_preempt_notifiers() and fire_sched_out_preempt_notifiers() are using hlist_for_each_entry(), which is not safe against entry removal during iteration. Inspection of the KVM code does not reveal any use of preempt_notifier_unregister() within the preempt notifiers. Therefore, fix the comment. Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431881590-1456-1-git-send-email-mathieu.desnoyers@efficios.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Srikar Dronamraju 提交于
When CONFIG_SCHEDSTATS is enabled, /proc/<pid>/sched prints almost all sched statistics except sum_sleep_runtime. Since sum_sleep_runtime is a good info to collect, add this it to /proc/<pid>/sched. Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433751041-11724-4-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Srikar Dronamraju 提交于
Within runnable tasks in /proc/sched_debug, vruntime is printed twice, once as tree-key and again as exec-runtime. Since exec-runtime isnt populated in !CONFIG_SCHEDSTATS, use this field to print wait_sum. Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433751041-11724-3-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Srikar Dronamraju 提交于
With !CONFIG_SCHEDSTATS, runnable tasks in /proc/sched_debug has too many columns than required. Fix this by printing appropriate columns. While at this, print sum_exec_runtime, since this information is available even in !CONFIG_SCHEDSTATS case. Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433751041-11724-2-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 07 6月, 2015 5 次提交
-
-
由 Rik van Riel 提交于
Changeset a43455a1 ("sched/numa: Ensure task_numa_migrate() checks the preferred node") fixes an issue where workloads would never converge on a fully loaded (or overloaded) system. However, it introduces a regression on less than fully loaded systems, where workloads converge on a few NUMA nodes, instead of properly staying spread out across the whole system. This leads to a reduction in available memory bandwidth, and usable CPU cache, with predictable performance problems. The root cause appears to be an interaction between the load balancer and NUMA balancing, where the short term load represented by the load balancer differs from the long term load the NUMA balancing code would like to base its decisions on. Simply reverting a43455a1 would re-introduce the non-convergence of workloads on fully loaded systems, so that is not a good option. As an aside, the check done before a43455a1 only applied to a task's preferred node, not to other candidate nodes in the system, so the converge-on-too-few-nodes problem still happens, just to a lesser degree. Instead, try to compensate for the impedance mismatch between the load balancer and NUMA balancing by only ever considering a lesser loaded node as a destination for NUMA balancing, regardless of whether the task is trying to move to the preferred node, or to another node. This patch also addresses the issue that a system with a single runnable thread would never migrate that thread to near its memory, introduced by 095bebf6 ("sched/numa: Do not move past the balance point if unbalanced"). A test where the main thread creates a large memory area, and spawns a worker thread to iterate over the memory (placed on another node by select_task_rq_fair), after which the main thread goes to sleep and waits for the worker thread to loop over all the memory now sees the worker thread migrated to where the memory is, instead of having all the memory migrated over like before. Jirka has run a number of performance tests on several systems: single instance SpecJBB 2005 performance is 7-15% higher on a 4 node system, with higher gains on systems with more cores per socket. Multi-instance SpecJBB 2005 (one per node), linpack, and stream see little or no changes with the revert of 095bebf6 and this patch. Reported-by: NArtem Bityutski <dedekind1@gmail.com> Reported-by: NJirka Hladky <jhladky@redhat.com> Tested-by: NJirka Hladky <jhladky@redhat.com> Tested-by: NArtem Bityutskiy <dedekind1@gmail.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NMel Gorman <mgorman@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150528095249.3083ade0@annuminas.surriel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Rik van Riel 提交于
Commit 095bebf6 ("sched/numa: Do not move past the balance point if unbalanced") broke convergence of workloads with just one runnable thread, by making it impossible for the one runnable thread on the system to move from one NUMA node to another. Instead, the thread would remain where it was, and pull all the memory across to its location, which is much slower than just migrating the thread to where the memory is. The next patch has a better fix for the issue that 095bebf6 tried to address. Reported-by: NJirka Hladky <jhladky@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dedekind1@gmail.com Cc: mgorman@suse.de Link: http://lkml.kernel.org/r/1432753468-7785-2-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Ben Segall 提交于
The optimized task selection logic optimistically selects a new task to run without first doing a full put_prev_task(). This is so that we can avoid a put/set on the common ancestors of the old and new task. Similarly, we should only call check_cfs_rq_runtime() to throttle eligible groups if they're part of the common ancestry, otherwise it is possible to end up with no eligible task in the simple task selection. Imagine: /root /prev /next /A /B If our optimistic selection ends up throttling /next, we goto simple and our put_prev_task() ends up throttling /prev, after which we're going to bug out in set_next_entity() because there aren't any tasks left. Avoid this scenario by only throttling common ancestors. Reported-by: NMohammed Naser <mnaser@vexxhost.com> Reported-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: NBen Segall <bsegall@google.com> [ munged Changelog ] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pjt@google.com Fixes: 678d5718 ("sched/fair: Optimize cgroup pick_next_task_fair()") Link: http://lkml.kernel.org/r/xm26wq1oswoq.fsf@sword-of-the-dawn.mtv.corp.google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Frederic Weisbecker 提交于
preempt_schedule_context() is a tracing safe preemption point but it's only used when CONFIG_CONTEXT_TRACKING=y. Other configs have tracing recursion issues since commit: b30f0e3f ("sched/preempt: Optimize preemption operations on __schedule() callers") introduced function based preemp_count_*() ops. Lets make it available on all configs and give it a more appropriate name for its new position. Reported-by: NFengguang Wu <fengguang.wu@intel.com> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433432349-1021-3-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Frederic Weisbecker 提交于
Since function tracing disables preemption, it needs a safe preemption point to use when preemption is re-enabled without worrying about tracing recursion. Ie: to avoid tracing recursion, that preemption point can't be traced (use of notrace qualifier) and it can't call any traceable function before that preemption point disables preemption itself, which disarms the recursion. preempt_schedule() was fine until commit: b30f0e3f ("sched/preempt: Optimize preemption operations on __schedule() callers") because PREEMPT_ACTIVE (which has the property to disable preemption and this disarm tracing preemption recursion) was set before calling any further function. But that commit introduced the use of preempt_count_add/sub() functions to set PREEMPT_ACTIVE and because these functions are called before preemption gets a chance to be disabled, we have a tracing recursion. preempt_schedule_context() is one of the possible preemption functions used by tracing. Its special purpose is to avoid tracing recursion against context tracking. Lets enhance this function to become more generally tracing safe by disabling preemption with raw accessors, such that no function is called before preemption gets disabled and disarm the tracing recursion. This function is going to become the specific tracing-safe preemption point in further commit. Reported-by: NFengguang Wu <fengguang.wu@intel.com> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1433432349-1021-2-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 19 5月, 2015 3 次提交
-
-
由 Rik van Riel 提交于
It is possible for fbq_classify_rq() to indicate that a CPU has tasks that should be moved to another NUMA node, but for migrate_improves_locality and migrate_degrades_locality to not identify those tasks. This patch always gives preference to preferred node evaluations, and only checks the number of faults when evaluating moves between two non-preferred nodes on a larger NUMA system. On a two node system, the number of faults is never evaluated. Either a task is about to be pulled off its preferred node, or migrated onto it. Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: mgorman@suse.de Link: http://lkml.kernel.org/r/20150514225936.35b91717@annuminas.surriel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Frederic Weisbecker 提交于
__schedule() disables preemption and some of its callers (the preempt_schedule*() family) also set PREEMPT_ACTIVE. So we have two preempt_count() modifications that could be performed at once. Lets remove the preemption disablement from __schedule() and pull this responsibility to its callers in order to optimize preempt_count() operations in a single place. Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431441711-29753-5-git-send-email-fweisbec@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Shaohua Li 提交于
block plug callback could sleep, so we introduce a parameter 'from_schedule' and corresponding drivers can use it to destinguish a schedule plug flush or a plug finish. Unfortunately io_schedule_out still uses blk_flush_plug(). This causes below output (Note, I added a might_sleep() in raid1_unplug to make it trigger faster, but the whole thing doesn't matter if I add might_sleep). In raid1/10, this can cause deadlock. This patch makes io_schedule_out always uses blk_schedule_flush_plug. This should only impact drivers (as far as I know, raid 1/10) which are sensitive to the 'from_schedule' parameter. [ 370.817949] ------------[ cut here ]------------ [ 370.817960] WARNING: CPU: 7 PID: 145 at ../kernel/sched/core.c:7306 __might_sleep+0x7f/0x90() [ 370.817969] do not call blocking ops when !TASK_RUNNING; state=2 set at [<ffffffff81092fcf>] prepare_to_wait+0x2f/0x90 [ 370.817971] Modules linked in: raid1 [ 370.817976] CPU: 7 PID: 145 Comm: kworker/u16:9 Tainted: G W 4.0.0+ #361 [ 370.817977] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014 [ 370.817983] Workqueue: writeback bdi_writeback_workfn (flush-9:1) [ 370.817985] ffffffff81cd83be ffff8800ba8cb298 ffffffff819dd7af 0000000000000001 [ 370.817988] ffff8800ba8cb2e8 ffff8800ba8cb2d8 ffffffff81051afc ffff8800ba8cb2c8 [ 370.817990] ffffffffa00061a8 000000000000041e 0000000000000000 ffff8800ba8cba28 [ 370.817993] Call Trace: [ 370.817999] [<ffffffff819dd7af>] dump_stack+0x4f/0x7b [ 370.818002] [<ffffffff81051afc>] warn_slowpath_common+0x8c/0xd0 [ 370.818004] [<ffffffff81051b86>] warn_slowpath_fmt+0x46/0x50 [ 370.818006] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818008] [<ffffffff81092fcf>] ? prepare_to_wait+0x2f/0x90 [ 370.818010] [<ffffffff810776ef>] __might_sleep+0x7f/0x90 [ 370.818014] [<ffffffffa0000c03>] raid1_unplug+0xd3/0x170 [raid1] [ 370.818024] [<ffffffff81421d9a>] blk_flush_plug_list+0x8a/0x1e0 [ 370.818028] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818031] [<ffffffff819e21b0>] io_schedule_timeout+0x130/0x140 [ 370.818033] [<ffffffff819e3586>] bit_wait_io+0x36/0x50 [ 370.818034] [<ffffffff819e31b5>] __wait_on_bit+0x65/0x90 [ 370.818041] [<ffffffff8125b67c>] ? ext4_read_block_bitmap_nowait+0xbc/0x630 [ 370.818043] [<ffffffff819e3550>] ? bit_wait+0x50/0x50 [ 370.818045] [<ffffffff819e3302>] out_of_line_wait_on_bit+0x72/0x80 [ 370.818047] [<ffffffff810935e0>] ? autoremove_wake_function+0x40/0x40 [ 370.818050] [<ffffffff811de744>] __wait_on_buffer+0x44/0x50 [ 370.818053] [<ffffffff8125ae80>] ext4_wait_block_bitmap+0xe0/0xf0 [ 370.818058] [<ffffffff812975d6>] ext4_mb_init_cache+0x206/0x790 [ 370.818062] [<ffffffff8114bc6c>] ? lru_cache_add+0x1c/0x50 [ 370.818064] [<ffffffff81297c7e>] ext4_mb_init_group+0x11e/0x200 [ 370.818066] [<ffffffff81298231>] ext4_mb_load_buddy+0x341/0x360 [ 370.818068] [<ffffffff8129a1a3>] ext4_mb_find_by_goal+0x93/0x2f0 [ 370.818070] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818072] [<ffffffff8129ab67>] ext4_mb_regular_allocator+0x67/0x460 [ 370.818074] [<ffffffff81295b54>] ? ext4_mb_normalize_request+0x1e4/0x5b0 [ 370.818076] [<ffffffff8129ca4b>] ext4_mb_new_blocks+0x4cb/0x620 [ 370.818079] [<ffffffff81290956>] ext4_ext_map_blocks+0x4c6/0x14d0 [ 370.818081] [<ffffffff812a4d4e>] ? ext4_es_lookup_extent+0x4e/0x290 [ 370.818085] [<ffffffff8126399d>] ext4_map_blocks+0x14d/0x4f0 [ 370.818088] [<ffffffff81266fbd>] ext4_writepages+0x76d/0xe50 [ 370.818094] [<ffffffff81149691>] do_writepages+0x21/0x50 [ 370.818097] [<ffffffff811d5c00>] __writeback_single_inode+0x60/0x490 [ 370.818099] [<ffffffff811d630a>] writeback_sb_inodes+0x2da/0x590 [ 370.818103] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818105] [<ffffffff811abf4b>] ? trylock_super+0x1b/0x50 [ 370.818107] [<ffffffff811d665f>] __writeback_inodes_wb+0x9f/0xd0 [ 370.818109] [<ffffffff811d69db>] wb_writeback+0x34b/0x3c0 [ 370.818111] [<ffffffff811d70df>] bdi_writeback_workfn+0x23f/0x550 [ 370.818116] [<ffffffff8106bbd8>] process_one_work+0x1c8/0x570 [ 370.818117] [<ffffffff8106bb5b>] ? process_one_work+0x14b/0x570 [ 370.818119] [<ffffffff8106c09b>] worker_thread+0x11b/0x470 [ 370.818121] [<ffffffff8106bf80>] ? process_one_work+0x570/0x570 [ 370.818124] [<ffffffff81071868>] kthread+0xf8/0x110 [ 370.818126] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818129] [<ffffffff819e9322>] ret_from_fork+0x42/0x70 [ 370.818131] [<ffffffff81071770>] ? kthread_create_on_node+0x210/0x210 [ 370.818132] ---[ end trace 7b4deb71e68b6605 ]--- V2: don't change ->in_iowait Cc: NeilBrown <neilb@suse.de> Signed-off-by: NShaohua Li <shli@fb.com> Reviewed-by: NJeff Moyer <jmoyer@redhat.com> Signed-off-by: NJens Axboe <axboe@fb.com>
-
- 17 5月, 2015 1 次提交
-
-
由 Nicholas Mc Guire 提交于
static code checking was unhappy with: ./kernel/sched/fair.c:162 WARNING: return of wrong type int != unsigned int get_update_sysctl_factor() is declared to return int but is currently returning an unsigned int. The first few preprocessed lines are: static int get_update_sysctl_factor(void) { unsigned int cpus = ({ int __min1 = (cpumask_weight(cpu_online_mask)); int __min2 = (8); __min1 < __min2 ? __min1: __min2; }); unsigned int factor; The type used by min_t() should be 'unsigned int' and the return type of get_update_sysctl_factor() should also be 'unsigned int' as its call-site update_sysctl() is expecting 'unsigned int' and the values utilizing: 'factor' 'sysctl_sched_min_granularity' 'sched_nr_latency' 'sysctl_sched_wakeup_granularity' ... are also all 'unsigned int', plus cpumask_weight() is also returning 'unsigned int'. So the natural type to use around here is 'unsigned int'. ( Patch was compile tested with x86_64_defconfig + CONFIG_SCHED_DEBUG=y and the changed sections in kernel/sched/fair.i were reviewed. ) Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org> [ Improved the changelog a bit. ] Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431716742-11077-1-git-send-email-hofrat@osadl.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 08 5月, 2015 10 次提交
-
-
由 Peter Zijlstra 提交于
This is useful for locking primitives that can effect multiple wakeups per operation and want to avoid lock internal lock contention by delaying the wakeups until we've released the lock internal locks. Alternatively it can be used to avoid issuing multiple wakeups, and thus save a few cycles, in packet processing. Queue all target tasks and wakeup once you've processed all packets. That way you avoid waking the target task multiple times if there were multiple packets for the same task. Properties of a wake_q are: - Lockless, as queue head must reside on the stack. - Being a queue, maintains wakeup order passed by the callers. This can be important for otherwise, in scenarios where highly contended locks could affect any reliance on lock fairness. - A queued task cannot be added again until it is woken up. This patch adds the needed infrastructure into the scheduler code and uses the new wake_list to delay the futex wakeups until after we've released the hash bucket locks. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> [tweaks, adjustments, comments, etc.] Signed-off-by: NDavidlohr Bueso <dbueso@suse.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Chris Mason <clm@fb.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: George Spelvin <linux@horizon.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1430494072-30283-2-git-send-email-dave@stgolabs.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Jason Low 提交于
Recent optimizations were made to thread_group_cputimer to improve its scalability by keeping track of cputime stats without a lock. However, the values were open coded to the structure, causing them to be at a different abstraction level from the regular task_cputime structure. Furthermore, any subsequent similar optimizations would not be able to share the new code, since they are specific to thread_group_cputimer. This patch adds the new task_cputime_atomic data structure (introduced in the previous patch in the series) to thread_group_cputimer for keeping track of the cputime atomically, which also helps generalize the code. Suggested-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NJason Low <jason.low2@hp.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NRik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1430251224-5764-6-git-send-email-jason.low2@hp.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Jason Low 提交于
While running a database workload, we found a scalability issue with itimers. Much of the problem was caused by the thread_group_cputimer spinlock. Each time we account for group system/user time, we need to obtain a thread_group_cputimer's spinlock to update the timers. On larger systems (such as a 16 socket machine), this caused more than 30% of total time spent trying to obtain this kernel lock to update these group timer stats. This patch converts the timers to 64-bit atomic variables and use atomic add to update them without a lock. With this patch, the percent of total time spent updating thread group cputimer timers was reduced from 30% down to less than 1%. Note: On 32-bit systems using the generic 64-bit atomics, this causes sample_group_cputimer() to take locks 3 times instead of just 1 time. However, we tested this patch on a 32-bit system ARM system using the generic atomics and did not find the overhead to be much of an issue. An explanation for why this isn't an issue is that 32-bit systems usually have small numbers of CPUs, and cacheline contention from extra spinlocks called periodically is not really apparent on smaller systems. Signed-off-by: NJason Low <jason.low2@hp.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NRik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1430251224-5764-4-git-send-email-jason.low2@hp.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Jason Low 提交于
The p->mm->numa_scan_seq is accessed using READ_ONCE/WRITE_ONCE and modified without exclusive access. It is not clear why it is accessed this way. This patch provides some documentation on that. Suggested-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NJason Low <jason.low2@hp.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NRik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <waiman.long@hp.com> Link: http://lkml.kernel.org/r/1430440094.2475.61.camel@j-VirtualBoxSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Jason Low 提交于
ACCESS_ONCE doesn't work reliably on non-scalar types. This patch removes the rest of the existing usages of ACCESS_ONCE() in the scheduler, and use the new READ_ONCE() and WRITE_ONCE() APIs as appropriate. Signed-off-by: NJason Low <jason.low2@hp.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NWaiman Long <Waiman.Long@hp.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1430251224-5764-2-git-send-email-jason.low2@hp.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Nicholas Mc Guire 提交于
'rt_period_us' is automatically type converted from u64 to long and then cast back to u64 - this down/up conversion is unnecessary and can be removed to improve readability. This will also help us not truncate 'rt_period_us' to 32 bits on 32-bit kernels, should we ever have so large values. (unlikely, not the least due to procfs.) Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1430643116-24049-1-git-send-email-hofrat@osadl.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Peter Zijlstra 提交于
I could not find the loadavg code.. turns out it was hidden in a file called proc.c. It further got mingled up with the cruft per rq load indexes (which we really want to get rid of). Move the per rq load indexes into the fair.c load-balance code (that's the only thing that uses them) and rename proc.c to loadavg.c so we can find it again. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> [ Did minor cleanups to the code. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Paul Gortmaker 提交于
We removed __cpuinit support (leaving no-op stubs) quite some time ago. However this one crept back in as of commit a803f026 ("sched: Initialize rq->age_stamp on processor start") Since we want to clobber the stubs too, get this removed now. Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Corey Minyard <cminyard@mvista.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1430174880-27958-2-git-send-email-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Omar Sandoval 提交于
Commit 3c18d447 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()"), a SCHED_DEADLINE bugfix, had a logic error that caused a regression in setting a CPU inactive during suspend. I ran into this when a program was failing pthread_setaffinity_np() with EINVAL after a suspend+wake up. A simple reproducer: $ ./a.out sched_setaffinity: Success $ systemctl suspend $ ./a.out sched_setaffinity: Invalid argument ... where ./a.out is: #define _GNU_SOURCE #include <errno.h> #include <sched.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> int main(void) { long num_cores; cpu_set_t cpu_set; int ret; num_cores = sysconf(_SC_NPROCESSORS_ONLN); CPU_ZERO(&cpu_set); CPU_SET(num_cores - 1, &cpu_set); errno = 0; ret = sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set); perror("sched_setaffinity"); return ret ? EXIT_FAILURE : EXIT_SUCCESS; } The mistake is that suspend is handled in the action == CPU_DOWN_PREPARE_FROZEN case of the switch statement in cpuset_cpu_inactive(). However, the commit in question masked out CPU_TASKS_FROZEN from the action, making this case dead. The fix is straightforward. Signed-off-by: NOmar Sandoval <osandov@osandov.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 3c18d447 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()") Link: http://lkml.kernel.org/r/1cb5ecb3d6543c38cce5790387f336f54ec8e2bc.1430733960.git.osandov@osandov.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Thomas Gleixner 提交于
Ronny reported that the following scenario is not handled correctly: T1 (prio = 10) lock(rtmutex); T2 (prio = 20) lock(rtmutex) boost T1 T1 (prio = 20) sys_set_scheduler(prio = 30) T1 prio = 30 .... sys_set_scheduler(prio = 10) T1 prio = 30 The last step is wrong as T1 should now be back at prio 20. Commit c365c292 ("sched: Consider pi boosting in setscheduler()") only handles the case where a boosted tasks tries to lower its priority. Fix it by taking the new effective priority into account for the decision whether a change of the priority is required. Reported-by: NRonny Meeus <ronny.meeus@gmail.com> Tested-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NSteven Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Fixes: c365c292 ("sched: Consider pi boosting in setscheduler()") Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1505051806060.4225@nanosSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 29 4月, 2015 1 次提交
-
-
由 Rafael J. Wysocki 提交于
Commit 335f4919 (sched/idle: Use explicit broadcast oneshot control function) replaced clockevents_notify() invocations in cpuidle_idle_call() with direct calls to tick_broadcast_enter() and tick_broadcast_exit(), but it overlooked the fact that interrupts were already enabled before calling the latter which led to functional breakage on systems using idle states with the CPUIDLE_FLAG_TIMER_STOP flag set. Fix that by moving the invocations of tick_broadcast_enter() and tick_broadcast_exit() down into cpuidle_enter_state() where interrupts are still disabled when tick_broadcast_exit() is called. Also ensure that interrupts will be disabled before running tick_broadcast_exit() even if they have been enabled by the idle state's ->enter callback. Trigger a WARN_ON_ONCE() in that case, as we generally don't want that to happen for states with CPUIDLE_FLAG_TIMER_STOP set. Fixes: 335f4919 (sched/idle: Use explicit broadcast oneshot control function) Reported-and-tested-by: NLinus Walleij <linus.walleij@linaro.org> Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org> Reported-and-tested-by: NSudeep Holla <sudeep.holla@arm.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
-
- 27 4月, 2015 1 次提交
-
-
由 Paolo Bonzini 提交于
This reverts commits 0a4e6be9 and 80f7fdb1. The task migration notifier was originally introduced in order to support the pvclock vsyscall with non-synchronized TSC, but KVM only supports it with synchronized TSC. Hence, on KVM the race condition is only needed due to a bad implementation on the host side, and even then it's so rare that it's mostly theoretical. As far as KVM is concerned it's possible to fix the host, avoiding the additional complexity in the vDSO and the (re)introduction of the task migration notifier. Xen, on the other hand, hasn't yet implemented vsyscall support at all, so we do not care about its plans for non-synchronized TSC. Reported-by: NPeter Zijlstra <peterz@infradead.org> Suggested-by: NMarcelo Tosatti <mtosatti@redhat.com> Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
-
- 16 4月, 2015 1 次提交
-
-
由 Tobias Klauser 提交于
Since commit: 029632fb ("sched: Make separate sched*.c translation units") autogroup is a separate translation unit built from the Makefile and thus no longer needs its content wrapped with #ifdef CONFIG_SCHED_AUTOGROUP. Signed-off-by: NTobias Klauser <tklauser@distanz.ch> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1429116678-17000-1-git-send-email-tklauser@distanz.chSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 08 4月, 2015 1 次提交
-
-
由 Naoya Horiguchi 提交于
Currently when a process accesses a hugetlb range protected with PROTNONE, unexpected COWs are triggered, which finally puts the hugetlb subsystem into a broken/uncontrollable state, where for example h->resv_huge_pages is subtracted too much and wraps around to a very large number, and the free hugepage pool is no longer maintainable. This patch simply stops changing protection for vma(VM_HUGETLB) to fix the problem. And this also allows us to avoid useless overhead of minor faults. Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com> Suggested-by: NMel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: David Rientjes <rientjes@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 03 4月, 2015 2 次提交
-
-
由 Borislav Petkov 提交于
Commit: 3c18d447 ("sched/core: Check for available DL bandwidth in cpuset_cpu_inactive()") forgot a trace_printk() debugging piece in and Steve's banner screamed in dmesg. Remove it. Signed-off-by: NBorislav Petkov <bp@suse.de> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1428050570-21041-1-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Thomas Gleixner 提交于
Replace the clockevents_notify() call with an explicit function call. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/6422336.RMm7oUHcXh@vostro.rjw.lanSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 02 4月, 2015 4 次提交
-
-
由 Wanpeng Li 提交于
I observed that DL tasks can't be migrated to other CPUs during CPU hotplug, in addition, task may/may not be running again if CPU is added back. The root cause which I found is that DL tasks will be throtted and removed from the DL rq after comsuming all their budget, which leads to the situation that stop task can't pick them up from the DL rq and migrate them to other CPUs during hotplug. The method to reproduce: schedtool -E -t 50000:100000 -e ./test Actually './test' is just a simple for loop. Then observe which CPU the test task is on and offline it: echo 0 > /sys/devices/system/cpu/cpuN/online This patch adds the DL task migration during CPU hotplug by finding a most suitable later deadline rq after DL timer fires if current rq is offline. If it fails to find a suitable later deadline rq then it falls back to any eligible online CPU in so that the deadline task will come back to us, and the push/pull mechanism should then move it around properly. Suggested-and-Acked-by: NJuri Lelli <juri.lelli@arm.com> Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427411315-4298-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Juri Lelli 提交于
Hotplug operations are destructive w.r.t. cpusets. In case such an operation is performed on a CPU belonging to an exlusive cpuset, the DL bandwidth information associated with the corresponding root domain is gone even if the operation fails (in sched_cpu_inactive()). For this reason we need to move the check we currently have in sched_cpu_inactive() to cpuset_cpu_inactive() to prevent useless cpusets reconfiguration in the CPU_DOWN_FAILED path. Signed-off-by: NJuri Lelli <juri.lelli@arm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@gmail.com> Link: http://lkml.kernel.org/r/1427792017-7356-2-git-send-email-juri.lelli@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Juri Lelli 提交于
dl_task_timer() may fire on a different rq from where a task was removed after throttling. Since the call path is: dl_task_timer() -> enqueue_task_dl() -> enqueue_dl_entity() -> replenish_dl_entity() and replenish_dl_entity() uses dl_se's rq, we can't use current's rq in dl_task_timer(), but we need to lock the task's previous one. Tested-by: NWanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: NJuri Lelli <juri.lelli@arm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NKirill Tkhai <ktkhai@parallels.com> Cc: Juri Lelli <juri.lelli@gmail.com> Fixes: 3960c8c0 ("sched: Make dl_task_time() use task_rq_lock()") Link: http://lkml.kernel.org/r/1427792017-7356-1-git-send-email-juri.lelli@arm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Abel Vesa 提交于
Obviously, 'rq' is not used in these two functions, therefore, there is no reason for it to be passed as an argument. Signed-off-by: NAbel Vesa <abelvesa@gmail.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1425383427-26244-1-git-send-email-abelvesa@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 27 3月, 2015 3 次提交
-
-
由 Wanpeng Li 提交于
One version of sched_rt_global_constaints() (the !rt-cgroup one) changes state, therefore if we fail the later sched_dl_global_constraints() call the state is left in an inconsistent state. Fix this by changing the order of the calls. Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> [ Improved the changelog. ] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJuri Lelli <juri.lelli@arm.com> Link: http://lkml.kernel.org/r/1426590931-4639-2-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Wanpeng Li 提交于
Since commit 40767b0d ("sched/deadline: Fix deadline parameter modification handling") we clear the thottled state when switching from a dl task, therefore we should never find it set in switching to a dl task. Signed-off-by: NWanpeng Li <wanpeng.li@linux.intel.com> [ Improved the changelog. ] Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: NJuri Lelli <juri.lelli@arm.com> Link: http://lkml.kernel.org/r/1426590931-4639-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Preeti U Murthy 提交于
When a CPU is kicked to do nohz idle balancing, it wakes up to do load balancing on itself, followed by load balancing on behalf of idle CPUs. But it may end up with load after the load balancing attempt on itself. This aborts nohz idle balancing. As a result several idle CPUs are left without tasks till such a time that an ILB CPU finds it unfavorable to pull tasks upon itself. This delays spreading of load across idle CPUs and worse, clutters only a few CPUs with tasks. The effect of the above problem was observed on an SMT8 POWER server with 2 levels of numa domains. Busy loops equal to number of cores were spawned. Since load balancing on fork/exec is discouraged across numa domains, all busy loops would start on one of the numa domains. However it was expected that eventually one busy loop would run per core across all domains due to nohz idle load balancing. But it was observed that it took as long as 10 seconds to spread the load across numa domains. Further investigation showed that this was a consequence of the following: 1. An ILB CPU was chosen from the first numa domain to trigger nohz idle load balancing [Given the experiment, upto 6 CPUs per core could be potentially idle in this domain.] 2. However the ILB CPU would call load_balance() on itself before initiating nohz idle load balancing. 3. Given cores are SMT8, the ILB CPU had enough opportunities to pull tasks from its sibling cores to even out load. 4. Now that the ILB CPU was no longer idle, it would abort nohz idle load balancing As a result the opportunities to spread load across numa domains were lost until such a time that the cores within the first numa domain had equal number of tasks among themselves. This is a pretty bad scenario, since the cores within the first numa domain would have as many as 4 tasks each, while cores in the neighbouring numa domains would all remain idle. Fix this, by checking if a CPU was woken up to do nohz idle load balancing, before it does load balancing upon itself. This way we allow idle CPUs across the system to do load balancing which results in quicker spread of load, instead of performing load balancing within the local sched domain hierarchy of the ILB CPU alone under circumstances such as above. Signed-off-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NJason Low <jason.low2@hp.com> Cc: benh@kernel.crashing.org Cc: daniel.lezcano@linaro.org Cc: efault@gmx.de Cc: iamjoonsoo.kim@lge.com Cc: morten.rasmussen@arm.com Cc: pjt@google.com Cc: riel@redhat.com Cc: srikar@linux.vnet.ibm.com Cc: svaidy@linux.vnet.ibm.com Cc: tim.c.chen@linux.intel.com Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/20150326130014.21532.17158.stgit@preeti.in.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
-