kernel.git/include/trace/events/sched.h, branch linux-3.13.y

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

2013-11-06T06:50:37Z

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

2013-10-31T10:16:18Z

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

2013-09-25T12:07:52Z

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

2013-08-14T01:05:57Z

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

tracing/perf: Expand TRACE_EVENT(sched_stat_runtime)

2013-08-14T01:05:12Z

To simplify the review of the next patches: 1. We are going to reimplent __perf_task/counter and embedd them into TP_ARGS(). expand TRACE_EVENT(sched_stat_runtime) into DECLARE_EVENT_CLASS() + DEFINE_EVENT(), this way they can use different TP_ARGS's. 2. Change perf_trace_##call() macro to do perf_fetch_caller_regs() right before perf_trace_buf_prepare(). This way it evaluates TP_ARGS() asap, the next patch explores this fact. Note: after 87f44bbc perf_trace_buf_prepare() doesn't need "struct pt_regs *regs", perhaps it makes sense to remove this argument. And perhaps we can teach perf_trace_buf_submit() to accept regs == NULL and do fetch_caller_regs(CALLER_ADDR1) in this case. 3. Cosmetic, but the typecast from "void*" buys nothing. It just adds the noise, remove it. Link: http://lkml.kernel.org/r/20130806160841.GA2736@redhat.com Acked-by: Peter Zijlstra Tested-by: David Ahern Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt

kthread: Prevent unpark race which puts threads on the wrong cpu

2013-04-12T12:18:43Z

The smpboot threads rely on the park/unpark mechanism which binds per cpu threads on a particular core. Though the functionality is racy: CPU0 CPU1 CPU2 unpark(T) wake_up_process(T) clear(SHOULD_PARK) T runs leave parkme() due to !SHOULD_PARK bind_to(CPU2) BUG_ON(wrong CPU) We cannot let the tasks move themself to the target CPU as one of those tasks is actually the migration thread itself, which requires that it starts running on the target cpu right away. The solution to this problem is to prevent wakeups in park mode which are not from unpark(). That way we can guarantee that the association of the task to the target cpu is working correctly. Add a new task state (TASK_PARKED) which prevents other wakeups and use this state explicitly for the unpark wakeup. Peter noticed: Also, since the task state is visible to userspace and all the parked tasks are still in the PID space, its a good hint in ps and friends that these tasks aren't really there for the moment. The migration thread has another related issue. CPU0 CPU1 Bring up CPU2 create_thread(T) park(T) wait_for_completion() parkme() complete() sched_set_stop_task() schedule(TASK_PARKED) The sched_set_stop_task() call is issued while the task is on the runqueue of CPU1 and that confuses the hell out of the stop_task class on that cpu. So we need the same synchronizaion before sched_set_stop_task(). Reported-by: Dave Jones Reported-and-tested-by: Dave Hansen Reported-and-tested-by: Borislav Petkov Acked-by: Peter Ziljstra Cc: Srivatsa S. Bhat Cc: dhillf@gmail.com Cc: Ingo Molnar Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304091635430.21884@ionos Signed-off-by: Thomas Gleixner

perf/trace: Add ability to set a target task for events

2012-07-31T15:02:05Z

A few events are interesting not only for a current task. For example, sched_stat_* events are interesting for a task which wakes up. For this reason, it will be good if such events will be delivered to a target task too. Now a target task can be set by using __perf_task(). The original idea and a draft patch belongs to Peter Zijlstra. I need these events for profiling sleep times. sched_switch is used for getting callchains and sched_stat_* is used for getting time periods. These events are combined in user space, then it can be analyzed by perf tools. Inspired-by: Peter Zijlstra Cc: Steven Rostedt Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Arun Sharma Signed-off-by: Andrew Vagin Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1342016098-213063-1-git-send-email-avagin@openvz.org Signed-off-by: Ingo Molnar

tracing, sched, vfs: Fix 'old_pid' usage in trace_sched_process_exec()

2012-03-31T09:53:22Z

1. TRACE_EVENT(sched_process_exec) forgets to actually use the old pid argument, it sets ->old_pid = p->pid. 2. search_binary_handler() uses the wrong pid number. tracepoint needs the global pid_t from the root namespace, while old_pid is the virtual pid number as it seen by the tracer/parent. With this patch we have two pid_t's in search_binary_handler(), not really nice. Perhaps we should switch to "struct pid*", but in this case it would be better to cleanup the current code first and move the "depth == 0" code outside. Signed-off-by: Oleg Nesterov Cc: David Smith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Denys Vlasenko Link: http://lkml.kernel.org/r/20120330162636.GA4857@redhat.com Signed-off-by: Ingo Molnar

Merge branch 'perf/urgent' into perf/core

2012-03-05T08:20:08Z

Conflicts: tools/perf/builtin-record.c tools/perf/builtin-top.c tools/perf/perf.h tools/perf/util/top.h Merge reason: resolve these cherry-picking conflicts. Signed-off-by: Ingo Molnar

tracepoint, vfs, sched: Add exec() tracepoint

2012-02-23T08:28:06Z

Added a minimal exec tracepoint. Exec is an important major event in the life of a task, like fork(), clone() or exit(), all of which we already trace. [ We also do scheduling re-balancing during exec() - so it's useful from a scheduler instrumentation POV as well. ] If you want to watch a task start up, when it gets exec'ed is a good place to start. With the addition of this tracepoint, exec's can be monitored and better picture of general system activity can be obtained. This tracepoint will also enable better process life tracking, allowing you to answer questions like "what process keeps starting up binary X?". This tracepoint can also be useful in ftrace filtering and trigger conditions: i.e. starting or stopping filtering when exec is called. Signed-off-by: David Smith Signed-off-by: Peter Zijlstra Cc: Steven Rostedt Cc: Christoph Hellwig Cc: Al Viro Cc: Andrew Morton Cc: Linus Torvalds Link: http://lkml.kernel.org/r/4F314D19.7030504@redhat.com Signed-off-by: Ingo Molnar