pm24.git/kernel/trace/trace.c, branch v3.4-rc2

tracing: Fix ent_size in trace output

2012-03-27T16:05:44Z

When reading the trace file, the records of each of the per_cpu buffers are examined to find the next event to print out. At the point of looking at the event, the size of the event is recorded. But if the first event is chosen, the other events in the other CPU buffers will reset the event size that is stored in the iterator descriptor, causing the event size passed to the output functions to be incorrect. In most cases this is not a problem, but for the case of stack traces, it is. With the change to the stack tracing to record a dynamic number of back traces, the output depends on the size of the entry instead of the fixed 8 back traces. When the entry size is not correct, the back traces would not be fully printed. Note, reading from the per-cpu trace files were not affected. Reported-by: Thomas Gleixner Tested-by: Thomas Gleixner Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt

tracing: Keep NMI watchdog from triggering when dumping trace

2012-03-02T03:06:48Z

As ftrace_dump() (called by ftrace_dump_on_oops) disables interrupts as it dumps its output to the console, it can keep interrupts disabled for long periods of time. This is likely to trigger the NMI watchdog, and it can disrupt the output of critical data. Add a touch_nmi_watchdog() to each event that is written to the screen to keep the NMI watchdog from affecting the output. Signed-off-by: Steven Rostedt

tracing/ring-buffer: Only have tracing_on disable tracing buffers

2012-02-22T20:50:28Z

As the ring-buffer code is being used by other facilities in the kernel, having tracing_on file disable *all* buffers is not a desired affect. It should only disable the ftrace buffers that are being used. Move the code into the trace.c file and use the buffer disabling for tracing_on() and tracing_off(). This way only the ftrace buffers will be affected by them and other kernel utilities will not be confused to why their output suddenly stopped. Signed-off-by: Steven Rostedt

ftrace: sched_switch plugin is deprecated

2012-02-13T14:14:47Z

Actually, sched_switch function tracer is merged into wakeup/wakeup_rt Update 'mini-HOWTO' for ftrace(Kernel function tracer). If we want to trace "sched:sched_switch" to trace sched_switch func, We may utilize event option.(e.g: trace-cmd list -e | grep sched) This patch is based on Linux-3.3.rc2-SMP-PREEMPT Link: http://lkml.kernel.org/r/1328695537-15081-1-git-send-email-geunsik.lim@gmail.com Cc: Randy Dunlap Signed-off-by: Geunsik Lim Signed-off-by: Steven Rostedt

Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2012-01-08T20:19:57Z

* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits) reiserfs: Properly display mount options in /proc/mounts vfs: prevent remount read-only if pending removes vfs: count unlinked inodes vfs: protect remounting superblock read-only vfs: keep list of mounts for each superblock vfs: switch ->show_options() to struct dentry * vfs: switch ->show_path() to struct dentry * vfs: switch ->show_devname() to struct dentry * vfs: switch ->show_stats to struct dentry * switch security_path_chmod() to struct path * vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb vfs: trim includes a bit switch mnt_namespace ->root to struct mount vfs: take /proc/*/mounts and friends to fs/proc_namespace.c vfs: opencode mntget() mnt_set_mountpoint() vfs: spread struct mount - remaining argument of next_mnt() vfs: move fsnotify junk to struct mount vfs: move mnt_devname vfs: move mnt_list to struct mount vfs: switch pnode.h macros to struct mount * ...

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-01-06T16:02:58Z

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (106 commits) perf kvm: Fix copy & paste error in description perf script: Kill script_spec__delete perf top: Fix a memory leak perf stat: Introduce get_ratio_color() helper perf session: Remove impossible condition check perf tools: Fix feature-bits rework fallout, remove unused variable perf script: Add generic perl handler to process events perf tools: Use for_each_set_bit() to iterate over feature flags perf tools: Unify handling of features when writing feature section perf report: Accept fifos as input file perf tools: Moving code in some files perf tools: Fix out-of-bound access to struct perf_session perf tools: Continue processing header on unknown features perf tools: Improve macros for struct feature_ops perf: builtin-record: Document and check that mmap_pages must be a power of two. perf: builtin-record: Provide advice if mmap'ing fails with EPERM. perf tools: Fix truncated annotation perf script: look up thread using tid instead of pid perf tools: Look up thread names for system wide profiling perf tools: Fix comm for processes with named threads ...

switch debugfs to umode_t

2012-01-04T03:54:56Z

Signed-off-by: Al Viro

trace: Allow ftrace_dump() to be called from modules

2011-12-11T18:31:25Z

Add an EXPORT_SYMBOL_GPL() so that rcutorture can dump the trace buffer upon detection of an RCU error. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

tracing: Add entries in buffer and total entries to default output header

2011-11-17T16:10:43Z

Knowing the number of event entries in the ring buffer compared to the total number that were written is useful information. The latency format gives this information and there's no reason that the default format does not. This information is now added to the default header, along with the number of online CPUs: # tracer: nop # # entries-in-buffer/entries-written: 159836/64690869 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | -0 [000] ...2 49.442971: local_touch_nmi <-cpu_idle -0 [000] d..2 49.442973: enter_idle <-cpu_idle -0 [000] d..2 49.442974: atomic_notifier_call_chain <-enter_idle -0 [000] d..2 49.442976: __atomic_notifier_call_chain <-atomic_notifier The above shows that the trace contains 159836 entries, but 64690869 were written. One could figure out that there were 64531033 entries that were dropped. Signed-off-by: Steven Rostedt

tracing: Add irq, preempt-count and need resched info to default trace output

2011-11-17T14:58:48Z

People keep asking how to get the preempt count, irq, and need resched info and we keep telling them to enable the latency format. Some developers think that traces without this info is completely useless, and for a lot of tasks it is useless. The first option was to enable the latency trace as the default format, but the header for the latency format is pretty useless for most tracers and it also does the timestamp in straight microseconds from the time the trace started. This is sometimes more difficult to read as the default trace is seconds from the start of boot up. Latency format: # tracer: nop # # nop latency trace v1.1.5 on 3.2.0-rc1-test+ # -------------------------------------------------------------------- # latency: 0 us, #159771/64234230, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 #P:4) # ----------------- # | task: -0 (uid:0 nice:0 policy:0 rt_prio:0) # ----------------- # # _------=> CPU# # / _-----=> irqs-off # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / delay # cmd pid ||||| time | caller # \ / ||||| \ | / migratio-6 0...2 41778231us+: rcu_note_context_switch <-__schedule migratio-6 0...2 41778233us : trace_rcu_utilization <-rcu_note_context_switch migratio-6 0...2 41778235us+: rcu_sched_qs <-rcu_note_context_switch migratio-6 0d..2 41778236us+: rcu_preempt_qs <-rcu_note_context_switch migratio-6 0...2 41778238us : trace_rcu_utilization <-rcu_note_context_switch migratio-6 0...2 41778239us+: debug_lockdep_rcu_enabled <-__schedule default format: # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | migration/0-6 [000] 50.025810: rcu_note_context_switch <-__schedule migration/0-6 [000] 50.025812: trace_rcu_utilization <-rcu_note_context_switch migration/0-6 [000] 50.025813: rcu_sched_qs <-rcu_note_context_switch migration/0-6 [000] 50.025815: rcu_preempt_qs <-rcu_note_context_switch migration/0-6 [000] 50.025817: trace_rcu_utilization <-rcu_note_context_switch migration/0-6 [000] 50.025818: debug_lockdep_rcu_enabled <-__schedule migration/0-6 [000] 50.025820: debug_lockdep_rcu_enabled <-__schedule The latency format header has latency information that is pretty meaningless for most tracers. Although some of the header is useful, and we can add that later to the default format as well. What is really useful with the latency format is the irqs-off, need-resched hard/softirq context and the preempt count. This commit adds the option irq-info which is on by default that adds this information: # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | -0 [000] d..2 49.309305: cpuidle_get_driver <-cpuidle_idle_call -0 [000] d..2 49.309307: mwait_idle <-cpu_idle -0 [000] d..2 49.309309: need_resched <-mwait_idle -0 [000] d..2 49.309310: test_ti_thread_flag <-need_resched -0 [000] d..2 49.309312: trace_power_start.constprop.13 <-mwait_idle -0 [000] d..2 49.309313: trace_cpu_idle <-mwait_idle -0 [000] d..2 49.309315: need_resched <-mwait_idle If a user wants the old format, they can disable the 'irq-info' option: # tracer: nop # # TASK-PID CPU# TIMESTAMP FUNCTION # | | | | | -0 [000] 49.309305: cpuidle_get_driver <-cpuidle_idle_call -0 [000] 49.309307: mwait_idle <-cpu_idle -0 [000] 49.309309: need_resched <-mwait_idle -0 [000] 49.309310: test_ti_thread_flag <-need_resched -0 [000] 49.309312: trace_power_start.constprop.13 <-mwait_idle -0 [000] 49.309313: trace_cpu_idle <-mwait_idle -0 [000] 49.309315: need_resched <-mwait_idle Requested-by: Thomas Gleixner Signed-off-by: Steven Rostedt