linux/kernel/trace/trace_workqueue.c, branch v2.6.30

trace_workqueues: fix empty line's output

2009-03-25T17:32:35Z

Empty lines separate cpus stat. After previous fix(trace_stat: keep original order) applied, the empty lines are displayed at incorrect position. Signed-off-by: Lai Jiangshan Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker LKML-Reference: <49C9F266.2060706@cn.fujitsu.com> Signed-off-by: Ingo Molnar

tracing: Don't use tracing_record_cmdline() in workqueue tracer fix

2009-03-13T01:23:47Z

commit c3ffc7a40b7e94b094efe1c8ab4e24370a782b65 "Don't use tracing_record_cmdline() in workqueue tracer" has a race window. find_task_by_vpid() requires task_list_lock(). LKML-Reference: <20090313090042.43CD.A69D9226@jp.fujitsu.com> Signed-off-by: KOSAKI Motohiro Signed-off-by: Steven Rostedt

Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

2009-03-10T21:55:31Z

tracing: remove funky whitespace in the trace code

2009-03-10T18:13:14Z

Impact: clean up There existed a lot of 's in the tracing code. This patch removes them. Signed-off-by: Steven Rostedt

tracing: Don't assume possible cpu list have continuous numbers

2009-03-10T09:20:30Z

"for (++cpu ; cpu < num_possible_cpus(); cpu++)" statement assumes possible cpus have continuous number - but that's a wrong assumption. Insted, cpumask_next() should be used. Signed-off-by: KOSAKI Motohiro Cc: Lai Jiangshan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <20090310104437.A480.A69D9226@jp.fujitsu.com> Signed-off-by: Ingo Molnar

tracing: Don't use tracing_record_cmdline() in workqueue tracer

2009-03-09T09:26:13Z

Impact: improve workqueue tracer output Currently, /sys/kernel/debug/tracing/trace_stat/workqueues can display wrong and strange thread names. Why? Currently, ftrace has tracing_record_cmdline()/trace_find_cmdline() convenience function that implements a task->comm string cache. This can avoid unnecessary memcpy overhead and the workqueue tracer uses it. However, in general, any trace statistics feature shouldn't use tracing_record_cmdline() because trace statistics can display very old process. Then comm cache can return wrong string because recent process overrides the cache. Fortunately, workqueue trace guarantees that displayed processes are live. Thus we can search comm string from PID at display time. % cat workqueues # CPU INSERTED EXECUTED NAME # | | | | 7 431913 431913 kondemand/7 7 0 0 tail 7 21 21 git 7 0 0 ls 7 9 9 cat 7 832632 832632 unix_chkpwd 7 236292 236292 ls Note: tail, git, ls, cat unix_chkpwd are obiously not workqueue thread. % cat workqueues # CPU INSERTED EXECUTED NAME # | | | | 7 510 510 kondemand/7 7 0 0 kmpathd/7 7 15 15 ata/7 7 0 0 aio/7 7 11 11 kblockd/7 7 1063 1063 work_on_cpu/7 7 167 167 events/7 Signed-off-by: KOSAKI Motohiro Cc: Lai Jiangshan Cc: Steven Rostedt Cc: Frederic Weisbecker Signed-off-by: Ingo Molnar

trace_workqueue: use percpu data for workqueue stat

2009-01-20T12:06:59Z

Impact: use percpu data instead of a global structure Use: static DEFINE_PER_CPU(struct workqueue_global_stats, all_workqueue_stat); instead of allocating a global structure. percpu data also works well on NUMA. Signed-off-by: Lai Jiangshan Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar

tracing: add a new workqueue tracer

2009-01-14T11:11:43Z

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 Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar