BMC/Intel-BMC/linux.git/include/trace/events/sched.h, branch dev-4.6

sched/core: Fix trace_sched_switch()

2015-10-06T15:08:15+00:00

__trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE user, move trace_sched_switch() from prepare_task_switch() to __schedule() and propagate the @preempt argument. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Steven Rostedt Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

sched: Introduce the 'trace_sched_waking' tracepoint

2015-08-03T10:21:22+00:00

Mathieu reported that since 317f394160e9 ("sched: Move the second half of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of context of the waker. This is a problem when you want to analyse wakeup paths because it is now very hard to correlate the wakeup event to whoever issued the wakeup. OTOH trace_sched_wakeup() is issued at the point where we set p->state = TASK_RUNNING, which is right were we hand the task off to the scheduler, so this is an important point when looking at scheduling behaviour, up to here its been the wakeup path everything hereafter is due to scheduler policy. To bridge this gap, introduce a second tracepoint: trace_sched_waking. It is guaranteed to be called in the waker context. Reported-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Cc: Francis Giraldeau Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20150609091336.GQ3644@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

sched/wait: Introduce TASK_NOLOAD and TASK_IDLE

2015-05-19T06:39:18+00:00

Currently people use TASK_INTERRUPTIBLE to idle kthreads and wait for 'work' because TASK_UNINTERRUPTIBLE contributes to the loadavg. Having all idle kthreads contribute to the loadavg is somewhat silly. Now mostly this works OK, because kthreads have all their signals masked. However there's a few sites where this is causing problems and TASK_UNINTERRUPTIBLE should be used, except for that loadavg issue. This patch adds TASK_NOLOAD which, when combined with TASK_UNINTERRUPTIBLE avoids the loadavg accounting. As most of imagined usage sites are loops where a thread wants to idle, waiting for work, a helper TASK_IDLE is introduced. Signed-off-by: Peter Zijlstra (Intel) Cc: Julian Anastasov Cc: Linus Torvalds Cc: NeilBrown Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar

sched: Fix the PREEMPT_ACTIVE check in __trace_sched_switch_state()

2014-10-28T09:47:53+00:00

task_preempt_count() has nothing to do with the actual preempt counter, thread_info->saved_preempt_count is only valid right after switch_to(). __trace_sched_switch_state() can use preempt_count(), prev is still the current task when trace_sched_switch() is called. Signed-off-by: Oleg Nesterov [ Added BUG_ON(). ] Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Andy Lutomirski Cc: Linus Torvalds Cc: Mel Gorman Cc: Oleg Nesterov Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20141007195108.GB28002@redhat.com Signed-off-by: Ingo Molnar

sched, trace: Add a tracepoint for IPI-less remote wakeups

2014-06-05T10:09:50+00:00

Remote wakeups of polling CPUs are a valuable performance improvement; add a tracepoint to make it much easier to verify that they're working. Signed-off-by: Andy Lutomirski Signed-off-by: Peter Zijlstra Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: umgwanakikbuti@gmail.com Cc: David Ahern Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Mel Gorman Cc: Oleg Nesterov Cc: Steven Rostedt Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/16205aee116772aa686814f9b13bccb562108047.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar

sched: add tracepoints related to NUMA task migration

2014-01-22T00:19:48+00:00

This patch adds three tracepoints o trace_sched_move_numa when a task is moved to a node o trace_sched_swap_numa when a task is swapped with another task o trace_sched_stick_numa when a numa-related migration fails The tracepoints allow the NUMA scheduler activity to be monitored and the following high-level metrics can be calculated o NUMA migrated stuck nr trace_sched_stick_numa o NUMA migrated idle nr trace_sched_move_numa o NUMA migrated swapped nr trace_sched_swap_numa o NUMA local swapped trace_sched_swap_numa src_nid == dst_nid (should never happen) o NUMA remote swapped trace_sched_swap_numa src_nid != dst_nid (should == NUMA migrated swapped) o NUMA group swapped trace_sched_swap_numa src_ngid == dst_ngid Maybe a small number of these are acceptable but a high number would be a major surprise. It would be even worse if bounces are frequent. o NUMA avg task migs. Average number of migrations for tasks o NUMA stddev task mig Self-explanatory o NUMA max task migs. Maximum number of migrations for a single task In general the intent of the tracepoints is to help diagnose problems where automatic NUMA balancing appears to be doing an excessive amount of useless work. [akpm@linux-foundation.org: remove semicolon-after-if, repair coding-style] Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Alex Thorlton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'sched/core' into core/locking, to prepare the kernel/locking/ file move

2013-11-06T06:50:37+00:00

Conflicts: kernel/Makefile There are conflicts in kernel/Makefile due to file moving in the scheduler tree - resolve them. Signed-off-by: Ingo Molnar

hung_task debugging: Add tracepoint to report the hang

2013-10-31T10:16:18+00:00

Currently check_hung_task() prints a warning if it detects the problem, but it is not convenient to watch the system logs if user-space wants to be notified about the hang. Add the new trace_sched_process_hang() into check_hung_task(), this way a user-space monitor can easily wait for the hang and potentially resolve a problem. Signed-off-by: Oleg Nesterov Cc: Dave Sullivan Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20131019161828.GA7439@redhat.com Signed-off-by: Ingo Molnar

sched: Create more preempt_count accessors

2013-09-25T12:07:52+00:00

We need a few special preempt_count accessors: - task_preempt_count() for when we're interested in the preemption count of another (non-running) task. - init_task_preempt_count() for properly initializing the preemption count. - init_idle_preempt_count() a special case of the above for the idle threads. With these no generic code ever touches thread_info::preempt_count anymore and architectures could choose to remove it. Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-jf5swrio8l78j37d06fzmo4r@git.kernel.org Signed-off-by: Ingo Molnar

tracing/perf: Reimplement TP_perf_assign() logic

2013-08-14T01:05:57+00:00

The next patch tries to avoid the costly perf_trace_buf_* calls when possible but there is a problem. We can only do this if __task == NULL, perf_tp_event(task != NULL) has the additional code for this case. Unfortunately, TP_perf_assign/__perf_xxx which changes the default values of __count/__task variables for perf_trace_buf_submit() is called "too late", after we already did perf_trace_buf_prepare(), and the optimization above can't work. So this patch simply embeds __perf_xxx() into TP_ARGS(), this way DECLARE_EVENT_CLASS() can use the result of assignments hidden in "args" right after ftrace_get_offsets_##call() which is mostly trivial. This allows us to have the fast-path "__task != NULL" check at the start, see the next patch. Link: http://lkml.kernel.org/r/20130806160844.GA2739@redhat.com Tested-by: David Ahern Acked-by: Peter Zijlstra Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt