linux-toradex.git/include/trace/events/sched.h, branch v6.6-rc5

sched/tracing: Append prev_state to tp args instead

2022-05-11T22:37:11+00:00

Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting
sched_switch event, 2022-01-20) added a new prev_state argument to the
sched_switch tracepoint, before the prev task_struct pointer.

This reordering of arguments broke BPF programs that use the raw
tracepoint (e.g. tp_btf programs). The type of the second argument has
changed and existing programs that assume a task_struct* argument
(e.g. for bpf_task_storage access) will now fail to verify.

If we instead append the new argument to the end, all existing programs
would continue to work and can conditionally extract the prev_state
argument on supported kernel versions.

Fixes: fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20)
Signed-off-by: Delyan Kratunov 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Steven Rostedt (Google) 
Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com

sched/tracing: Don't re-read p->state when emitting sched_switch event

2022-03-01T15:18:39+00:00

As of commit

  c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu")

the following sequence becomes possible:

		      p->__state = TASK_INTERRUPTIBLE;
		      __schedule()
			deactivate_task(p);
  ttwu()
    READ !p->on_rq
    p->__state=TASK_WAKING
			trace_sched_switch()
			  __trace_sched_switch_state()
			    task_state_index()
			      return 0;

TASK_WAKING isn't in TASK_REPORT, so the task appears as TASK_RUNNING in
the trace event.

Prevent this by pushing the value read from __schedule() down the trace
event.

Reported-by: Abhijeet Dharmapurikar 
Signed-off-by: Valentin Schneider 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Steven Rostedt (Google) 
Link: https://lore.kernel.org/r/20220120162520.570782-2-valentin.schneider@arm.com

sched/tracing: Remove the redundant 'success' in the sched tracepoint

2021-06-10T15:16:20+00:00

'success' is left here for a long time and also it is meaningless
for the upper user. Just remove it.

[ There were some tools expecting this, and this may break them. But
  hopefully they've been fixed in the mean time. Otherwise this may be
  likely reverted - SDR ]

Link: https://lkml.kernel.org/r/20210422122226.9415-1-ed.tsai@mediatek.com

Cc: Peter Zijlstra 
Signed-off-by: Ed Tsai 
Signed-off-by: Steven Rostedt (VMware)

tracing: Fix various typos in comments

2021-03-23T18:08:18+00:00

Fix ~59 single-word typos in the tracing code comments, and fix
the grammar in a handful of places.

Link: https://lore.kernel.org/r/20210322224546.GA1981273@gmail.com
Link: https://lkml.kernel.org/r/20210323174935.GA4176821@gmail.com

Reviewed-by: Randy Dunlap 
Signed-off-by: Ingo Molnar 
Signed-off-by: Steven Rostedt (VMware)

kthread: remove comments about old _do_fork() helper

2021-01-11T14:11:56+00:00

The old _do_fork() helper has been removed in favor of kernel_clone().
Here correct some comments which still contain _do_fork()

Link: https://lore.kernel.org/r/20210111104807.18022-1-yanfei.xu@windriver.com
Cc: christian@brauner.io
Cc: linux-kernel@vger.kernel.org
Acked-by: Christian Brauner 
Signed-off-by: Yanfei Xu 
Signed-off-by: Christian Brauner

kthread: add kthread_work tracepoints

2020-12-15T20:13:36+00:00

While migrating some code from wq to kthread_worker, I found that I missed
the execute_start/end tracepoints.  So add similar tracepoints for
kthread_work.  And for completeness, queue_work tracepoint (although this
one differs slightly from the matching workqueue tracepoint).

Link: https://lkml.kernel.org/r/20201010180323.126634-1-robdclark@gmail.com
Signed-off-by: Rob Clark 
Cc: Rob Clark 
Cc: Steven Rostedt 
Cc: Ingo Molnar 
Cc: "Peter Zijlstra (Intel)" 
Cc: Phil Auld 
Cc: Valentin Schneider 
Cc: Thara Gopinath 
Cc: Randy Dunlap 
Cc: Vincent Donnefort 
Cc: Mel Gorman 
Cc: Jens Axboe 
Cc: Marcelo Tosatti 
Cc: Frederic Weisbecker 
Cc: Ilias Stamatis 
Cc: Liang Chen 
Cc: Ben Dooks 
Cc: Peter Zijlstra 
Cc: "J. Bruce Fields" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sched/debug: Add new tracepoint to track cpu_capacity

2020-10-03T14:30:52+00:00

rq->cpu_capacity is a key element in several scheduler parts, such as EAS
task placement and load balancing. Tracking this value enables testing
and/or debugging by a toolkit.

Signed-off-by: Vincent Donnefort 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/1598605249-72651-1-git-send-email-vincent.donnefort@arm.com

trace/events/sched.h: fix duplicated word

2020-07-22T08:22:05+00:00

Change "It it" to "It is".

Signed-off-by: Randy Dunlap 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/25305c1d-4ee8-e091-d20f-e700ddad49fd@infradead.org

sched: Add a tracepoint to track rq->nr_running

2020-07-08T09:39:02+00:00

Add a bare tracepoint trace_sched_update_nr_running_tp which tracks
->nr_running CPU's rq. This is used to accurately trace this data and
provide a visualization of scheduler imbalances in, for example, the
form of a heat map.  The tracepoint is accessed by loading an external
kernel module. An example module (forked from Qais' module and including
the pelt related tracepoints) can be found at:

  https://github.com/auldp/tracepoints-helpers.git

A script to turn the trace-cmd report output into a heatmap plot can be
found at:

  https://github.com/jirvoz/plot-nr-running

The tracepoints are added to add_nr_running() and sub_nr_running() which
are in kernel/sched/sched.h. In order to avoid CREATE_TRACE_POINTS in
the header a wrapper call is used and the trace/events/sched.h include
is moved before sched.h in kernel/sched/core.

Signed-off-by: Phil Auld 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://lkml.kernel.org/r/20200629192303.GC120228@lorien.usersys.redhat.com

sched/debug: Add new tracepoints to track util_est

2020-06-15T12:10:02+00:00

The util_est signals are key elements for EAS task placement and
frequency selection. Having tracepoints to track these signals enables
load-tracking and schedutil testing and/or debugging by a toolkit.

Signed-off-by: Vincent Donnefort 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Valentin Schneider 
Link: https://lkml.kernel.org/r/1590597554-370150-1-git-send-email-vincent.donnefort@arm.com