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
# | | | |||| | |
<idle>-0 [000] ...2 49.442971: local_touch_nmi <-cpu_idle
<idle>-0 [000] d..2 49.442973: enter_idle <-cpu_idle
<idle>-0 [000] d..2 49.442974: atomic_notifier_call_chain <-enter_idle
<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 <rostedt@goodmis.org>
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
# | | | |||| | |
<idle>-0 [000] d..2 49.309305: cpuidle_get_driver <-cpuidle_idle_call
<idle>-0 [000] d..2 49.309307: mwait_idle <-cpu_idle
<idle>-0 [000] d..2 49.309309: need_resched <-mwait_idle
<idle>-0 [000] d..2 49.309310: test_ti_thread_flag <-need_resched
<idle>-0 [000] d..2 49.309312: trace_power_start.constprop.13 <-mwait_idle
<idle>-0 [000] d..2 49.309313: trace_cpu_idle <-mwait_idle
<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
# | | | | |
<idle>-0 [000] 49.309305: cpuidle_get_driver <-cpuidle_idle_call
<idle>-0 [000] 49.309307: mwait_idle <-cpu_idle
<idle>-0 [000] 49.309309: need_resched <-mwait_idle
<idle>-0 [000] 49.309310: test_ti_thread_flag <-need_resched
<idle>-0 [000] 49.309312: trace_power_start.constprop.13 <-mwait_idle
<idle>-0 [000] 49.309313: trace_cpu_idle <-mwait_idle
<idle>-0 [000] 49.309315: need_resched <-mwait_idle
Requested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch solves the following problem:
Now some samples may be lost due to throttling. The number of samples is
restricted by sysctl_perf_event_sample_rate/HZ. A trace event is
divided on some samples according to event's period. I don't sure, that
we should generate more than one sample on each trace event. I think the
better way to use SAMPLE_PERIOD.
E.g.: I want to trace when a process sleeps. I created a process, which
sleeps for 1ms and for 4ms. perf got 100 events in both cases.
swapper 0 [000] 1141.371830: sched_stat_sleep: comm=foo pid=1801 delay=1386750 [ns]
swapper 0 [000] 1141.369444: sched_stat_sleep: comm=foo pid=1801 delay=4499585 [ns]
In the first case a kernel want to send 4499585 events and
in the second case it wants to send 1386750 events.
perf-reports shows that process sleeps in both places equal time. It's
bug.
With this patch kernel generates one event on each "sleep" and the time
slice is saved in the field "period". Perf knows how handle it.
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1320670457-2633428-3-git-send-email-avagin@openvz.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
drivers/media: video/a5k6aa is a module and so needs module.h
mfd: fix build failures in recently added ab5500 code
hwspinlock/u8500: include linux/module.h
MTD: MAPS: bcm963xx-flash.c: explicitly include module.h
* 'for-linus' of git://neil.brown.name/md:
md/raid5: STRIPE_ACTIVE has lock semantics, add barriers
md/raid5: abort any pending parity operations when array fails.
* 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs: (45 commits)
DocBook/drm: Clean up a todo-note
DocBook/drm: `device aware' -> `device-aware'
DocBook/drm: `(device|driver) specific' -> `(device|driver)-specific'
DocBook/drm: Clean up the paragraph on framebuffer objects
DocBook/drm: Use `; otherwise,'
DocBook/drm: Better flow with `, and then'
DocBook/drm: Refer to the domain-setting function as a device-specific ioctl
DocBook/drm: Improve flow of GPU/CPU coherence sentence
DocBook/drm: Use an <itemizelist> for fundamental GEM operations
DocBook/drm: Insert a comma
DocBook/drm: Use a <variablelist> for vblank ioctls
DocBook/drm: Use an itemizedlist for what an encoder needs to provide
DocBook/drm: Insert `the' for readability, and change `set' to `setting'
DocBook/drm: Remove extraneous commas
DocBook/drm: Use a colon
DocBook/drm: Clarify `final initialization' via better formatting
DocBook/drm: Remove redundancy
DocBook/drm: Insert `it' for smooth reading
DocBook/drm: The word `so-called'; I do not think it connotes what you think it connotes
DocBook/drm: Use a singular subject for grammatical cleanliness
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest: (21 commits)
ktest: Evaluate variables entered on the command line
ktest: Add variable ${PWD}
ktest: Add another monitor flush before installing kernel
ktest: Do not opencode reboot in grub setting
ktest: Add processing of complex conditionals
ktest: Fix parsing of config section lines
ktest: Sort make_min_config configs by dependecies
ktest: Add DEFINED keyword for IF statements
ktest: Add OVERRIDE keyword to DEFAULTS section
ktest: Consolidate TEST_TYPE and DEFAULT code
ktest: Add INCLUDE keyword to include other config files
ktest: Let IF keyword take comparisons
ktest: Add IF and ELSE to config sections
ktest: Do not reboot on config or build issues
ktest: Add option REBOOT_SUCCESS_LINE to stop waiting after a reboot
ktest: Add NO_INSTALL option to not install for a test
ktest: Fail when grub menu not found
ktest: Include monitor in reboot code
ktest: Only need to save .config when doing mrproper
ktest: Create outputdir if it does not exist
...
Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))
[The semantic patch that makes this change is available
in scripts/coccinelle/api/err_cast.cocci.
More information about semantic patching is available at
http://coccinelle.lip6.fr/]
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock:
hwspinlock/u8500: fix build error due to undefined label
hwspinlock: Don't return a value in __hwspin_unlock
Otherwise we get compile errors like this:
ERROR: "led_classdev_unregister" [drivers/platform/x86/dell-laptop.ko] undefined!
ERROR: "led_classdev_register" [drivers/platform/x86/dell-laptop.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
when the dell-laptop support is enabled without the necessary LED
support being enabled.
Reported-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file uses core functions like module_init() and module_exit()
and so it explicitly needs to include the module.h header.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Alek Du reported that the code erroneously applies time to jiffies
conversions twice to the t1 and t2 values. In normal use on a modem link
this cases no visible problem but on a slower link it will break as with
HZ=1000 as is typical we are running t1/t2 ten times too fast.
Alek's original patch removed the conversion from the timer setting but we
in fact have to be more careful as the contents of t1/t2 are visible via
the device API and we thus need to correct the constants.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix below build error:
CC drivers/hwspinlock/u8500_hsem.o
drivers/hwspinlock/u8500_hsem.c: In function 'u8500_hsem_probe':
drivers/hwspinlock/u8500_hsem.c:113: error: label 'free_state' used but not defined
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Fix below build warning:
CC arch/arm/mach-omap2/hwspinlock.o
In file included from arch/arm/mach-omap2/hwspinlock.c:22:
include/linux/hwspinlock.h: In function '__hwspin_unlock':
include/linux/hwspinlock.h:121: warning: 'return' with a value, in function returning void
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
All updates that occur under STRIPE_ACTIVE should be globally visible
when STRIPE_ACTIVE clears. test_and_set_bit() implies a barrier, but
clear_bit() does not.
This is suitable for 3.1-stable.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
When the number of failed devices exceeds the allowed number
we must abort any active parity operations (checks or updates) as they
are no longer meaningful, and can lead to a BUG_ON in
handle_parity_checks6.
This bug was introduce by commit 6c0069c0ae
in 2.6.29.
Reported-by: Manish Katiyar <mkatiyar@gmail.com>
Tested-by: Manish Katiyar <mkatiyar@gmail.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
These files had implicit dependencies on modular support
which now show up as build failures with the module cleanup
work merged to mainline.
Reported-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Include module.h to fix below build error:
CC drivers/hwspinlock/u8500_hsem.o
drivers/hwspinlock/u8500_hsem.c:177: error: 'THIS_MODULE' undeclared here (not in a function)
[...]
drivers/hwspinlock/u8500_hsem.c:196: warning: type defaults to 'int' in declaration of 'MODULE_AUTHOR'
drivers/hwspinlock/u8500_hsem.c:196: warning: function declaration isn't a prototype
make[2]: *** [drivers/hwspinlock/u8500_hsem.o] Error 1
make[1]: *** [drivers/hwspinlock] Error 2
make: *** [drivers] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
module.h was previously implicitly included through mtd/mtd.h.
Fixes the following build failure after the module.h cleanup:
CC drivers/mtd/maps/bcm963xx-flash.o
drivers/mtd/maps/bcm963xx-flash.c: In function 'bcm963xx_probe':
drivers/mtd/maps/bcm963xx-flash.c:208:29: error: 'THIS_MODULE' undeclared (first use in this function)
[...]
drivers/mtd/maps/bcm963xx-flash.c:276:1: warning: type defaults to 'int' in declaration of 'MODULE_AUTHOR'
drivers/mtd/maps/bcm963xx-flash.c:276:15: warning: function declaration isn't a prototype
make[7]: *** [drivers/mtd/maps/bcm963xx-flash.o] Error 1
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
