linux_dsm_epyc7002/kernel/trace
Frederic Weisbecker e1d8aa9f1d tracing: add a new workqueue tracer
Impact: new tracer

The workqueue tracer provides some statistical informations
about each cpu workqueue thread such as the number of the
works inserted and executed since their creation. It can help
to evaluate the amount of work each of them have to perform.
For example it can help a developer to decide whether he should
choose a per cpu workqueue instead of a singlethreaded one.

It only traces statistical informations for now but it will probably later
provide event tracing too.

Such a tracer could help too, and be improved, to help rt priority sorted
workqueue development.

To have a snapshot of the workqueues state at any time, just do

cat /debugfs/tracing/trace_stat/workqueues

Ie:

  1    125        125       reiserfs/1
  1      0          0       scsi_tgtd/1
  1      0          0       aio/1
  1      0          0       ata/1
  1    114        114       kblockd/1
  1      0          0       kintegrityd/1
  1   2147       2147       events/1

  0      0          0       kpsmoused
  0    105        105       reiserfs/0
  0      0          0       scsi_tgtd/0
  0      0          0       aio/0
  0      0          0       ata_aux
  0      0          0       ata/0
  0      0          0       cqueue
  0      0          0       kacpi_notify
  0      0          0       kacpid
  0    149        149       kblockd/0
  0      0          0       kintegrityd/0
  0   1000       1000       khelper
  0   2270       2270       events/0

Changes in V2:

_ Drop the static array based on NR_CPU and dynamically allocate the stat array
  with num_possible_cpus() and other cpu mask facilities....
_ Trace workqueue insertion at a bit lower level (insert_work instead of queue_work) to handle
  even the workqueue barriers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-14 12:11:43 +01:00
..
ftrace.c ftrace, ia64: Add macro for ftrace_caller 2009-01-14 12:11:18 +01:00
Kconfig tracing: add a new workqueue tracer 2009-01-14 12:11:43 +01:00
kmemtrace.c kmemtrace: add kmemtrace_init() 2009-01-06 10:16:35 +01:00
Makefile tracing: add a new workqueue tracer 2009-01-14 12:11:43 +01:00
ring_buffer.c kernel/trace/ring_buffer.c: use DIV_ROUND_UP 2009-01-11 03:44:32 +01:00
trace_boot.c Merge branches 'tracing/kmemtrace2' and 'tracing/ftrace' into tracing/urgent 2009-01-06 10:18:43 +01:00
trace_branch.c tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00
trace_functions_graph.c Merge branches 'tracing/kmemtrace2' and 'tracing/ftrace' into tracing/urgent 2009-01-06 10:18:43 +01:00
trace_functions.c ftrace: introduce tracing_reset_online_cpus() helper 2008-12-19 16:29:34 +01:00
trace_hw_branches.c Merge branches 'tracing/kmemtrace2' and 'tracing/ftrace' into tracing/urgent 2009-01-06 10:18:43 +01:00
trace_irqsoff.c tracing/ftrace: change the type of the init() callback 2008-11-16 07:55:23 +01:00
trace_mmiotrace.c mmiotrace: count events lost due to not recording 2009-01-11 04:01:30 +01:00
trace_nop.c tracing/ftrace: make nop tracer using tracer flags 2008-11-18 11:10:59 +01:00
trace_output.c ftrace: change trace.c to use registered events 2008-12-29 12:46:12 +01:00
trace_output.h ftrace: change trace.c to use registered events 2008-12-29 12:46:12 +01:00
trace_power.c Merge branches 'tracing/kmemtrace2' and 'tracing/ftrace' into tracing/urgent 2009-01-06 10:18:43 +01:00
trace_sched_switch.c sched, trace: update trace_sched_wakeup() 2008-12-25 13:10:21 +01:00
trace_sched_wakeup.c sched, trace: update trace_sched_wakeup() 2008-12-25 13:10:21 +01:00
trace_selftest_dynamic.c ftrace: fix dynamic ftrace selftest 2008-05-23 21:13:23 +02:00
trace_selftest.c tracing/selftest: remove TRACE_CONT reference 2008-12-29 15:07:47 +01:00
trace_stack.c trace: better use of stack_trace_enabled for boot up code 2008-12-18 12:56:56 +01:00
trace_stat.c tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00
trace_stat.h tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00
trace_sysprof.c cpumask: convert kernel trace functions 2009-01-01 10:12:22 +10:30
trace_workqueue.c tracing: add a new workqueue tracer 2009-01-14 12:11:43 +01:00
trace.c tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00
trace.h tracing/ftrace: separate events tracing and stats tracing engine 2009-01-14 12:11:37 +01:00