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authorLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 03:15:23 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-07-03 03:15:23 +0400
commitf0bb4c0ab064a8aeeffbda1cee380151a594eaab (patch)
tree14d55a89c5db455aa10ff9a96ca14c474a9c4d55 /Documentation
parenta4883ef6af5e513a1e8c2ab9aab721604aa3a4f5 (diff)
parent983433b5812c5cf33a9008fa38c6f9b407fedb76 (diff)
downloadlinux-f0bb4c0ab064a8aeeffbda1cee380151a594eaab.tar.xz
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar: "Kernel improvements: - watchdog driver improvements by Li Zefan - Power7 CPI stack events related improvements by Sukadev Bhattiprolu - event multiplexing via hrtimers and other improvements by Stephane Eranian - kernel stack use optimization by Andrew Hunter - AMD IOMMU uncore PMU support by Suravee Suthikulpanit - NMI handling rate-limits by Dave Hansen - various hw_breakpoint fixes by Oleg Nesterov - hw_breakpoint overflow period sampling and related signal handling fixes by Jiri Olsa - Intel Haswell PMU support by Andi Kleen Tooling improvements: - Reset SIGTERM handler in workload child process, fix from David Ahern. - Makefile reorganization, prep work for Kconfig patches, from Jiri Olsa. - Add automated make test suite, from Jiri Olsa. - Add --percent-limit option to 'top' and 'report', from Namhyung Kim. - Sorting improvements, from Namhyung Kim. - Expand definition of sysfs format attribute, from Michael Ellerman. Tooling fixes: - 'perf tests' fixes from Jiri Olsa. - Make Power7 CPI stack events available in sysfs, from Sukadev Bhattiprolu. - Handle death by SIGTERM in 'perf record', fix from David Ahern. - Fix printing of perf_event_paranoid message, from David Ahern. - Handle realloc failures in 'perf kvm', from David Ahern. - Fix divide by 0 in variance, from David Ahern. - Save parent pid in thread struct, from David Ahern. - Handle JITed code in shared memory, from Andi Kleen. - Fixes for 'perf diff', from Jiri Olsa. - Remove some unused struct members, from Jiri Olsa. - Add missing liblk.a dependency for python/perf.so, fix from Jiri Olsa. - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent. - No need to do locking when adding hists in perf report, only 'top' needs that, from Namhyung Kim. - Fix alignment of symbol column in in the hists browser (top, report) when -v is given, from NAmhyung Kim. - Fix 'perf top' -E option behavior, from Namhyung Kim. - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu. - Fix compile errors in bp_signal 'perf test', from Sukadev Bhattiprolu. ... and more things" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits) perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable() perf/x86: Fix shared register mutual exclusion enforcement perf/x86/intel: Support full width counting x86: Add NMI duration tracepoints perf: Drop sample rate when sampling is too slow x86: Warn when NMI handlers take large amounts of time hw_breakpoint: Introduce "struct bp_cpuinfo" hw_breakpoint: Simplify *register_wide_hw_breakpoint() hw_breakpoint: Introduce cpumask_of_bp() hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths perf/x86/intel: Add mem-loads/stores support for Haswell perf/x86/intel: Support Haswell/v4 LBR format perf/x86/intel: Move NMI clearing to end of PMI handler perf/x86/intel: Add Haswell PEBS support perf/x86/intel: Add simple Haswell PMU support perf/x86/intel: Add Haswell PEBS record support perf/x86/intel: Fix sparse warning perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation perf/x86/amd: Add IOMMU Performance Counter resource management ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-event_source-devices-events32
-rw-r--r--Documentation/ABI/testing/sysfs-bus-event_source-devices-format6
-rw-r--r--Documentation/sysctl/kernel.txt50
-rw-r--r--Documentation/trace/events-nmi.txt43
4 files changed, 116 insertions, 15 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 0adeb524c0d4..8b25ffb42562 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
@@ -27,14 +27,36 @@ Description: Generic performance monitoring events
"basename".
-What: /sys/devices/cpu/events/PM_LD_MISS_L1
- /sys/devices/cpu/events/PM_LD_REF_L1
- /sys/devices/cpu/events/PM_CYC
+What: /sys/devices/cpu/events/PM_1PLUS_PPC_CMPL
/sys/devices/cpu/events/PM_BRU_FIN
- /sys/devices/cpu/events/PM_GCT_NOSLOT_CYC
/sys/devices/cpu/events/PM_BRU_MPRED
- /sys/devices/cpu/events/PM_INST_CMPL
/sys/devices/cpu/events/PM_CMPLU_STALL
+ /sys/devices/cpu/events/PM_CMPLU_STALL_BRU
+ /sys/devices/cpu/events/PM_CMPLU_STALL_DCACHE_MISS
+ /sys/devices/cpu/events/PM_CMPLU_STALL_DFU
+ /sys/devices/cpu/events/PM_CMPLU_STALL_DIV
+ /sys/devices/cpu/events/PM_CMPLU_STALL_ERAT_MISS
+ /sys/devices/cpu/events/PM_CMPLU_STALL_FXU
+ /sys/devices/cpu/events/PM_CMPLU_STALL_IFU
+ /sys/devices/cpu/events/PM_CMPLU_STALL_LSU
+ /sys/devices/cpu/events/PM_CMPLU_STALL_REJECT
+ /sys/devices/cpu/events/PM_CMPLU_STALL_SCALAR
+ /sys/devices/cpu/events/PM_CMPLU_STALL_SCALAR_LONG
+ /sys/devices/cpu/events/PM_CMPLU_STALL_STORE
+ /sys/devices/cpu/events/PM_CMPLU_STALL_THRD
+ /sys/devices/cpu/events/PM_CMPLU_STALL_VECTOR
+ /sys/devices/cpu/events/PM_CMPLU_STALL_VECTOR_LONG
+ /sys/devices/cpu/events/PM_CYC
+ /sys/devices/cpu/events/PM_GCT_NOSLOT_BR_MPRED
+ /sys/devices/cpu/events/PM_GCT_NOSLOT_BR_MPRED_IC_MISS
+ /sys/devices/cpu/events/PM_GCT_NOSLOT_CYC
+ /sys/devices/cpu/events/PM_GCT_NOSLOT_IC_MISS
+ /sys/devices/cpu/events/PM_GRP_CMPL
+ /sys/devices/cpu/events/PM_INST_CMPL
+ /sys/devices/cpu/events/PM_LD_MISS_L1
+ /sys/devices/cpu/events/PM_LD_REF_L1
+ /sys/devices/cpu/events/PM_RUN_CYC
+ /sys/devices/cpu/events/PM_RUN_INST_CMPL
Date: 2013/01/08
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
index 079afc71363d..77f47ff5ee02 100644
--- a/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-format
@@ -9,6 +9,12 @@ Description:
we want to export, so that userspace can deal with sane
name/value pairs.
+ Userspace must be prepared for the possibility that attributes
+ define overlapping bit ranges. For example:
+ attr1 = 'config:0-23'
+ attr2 = 'config:0-7'
+ attr3 = 'config:12-35'
+
Example: 'config1:1,6-10,44'
Defines contents of attribute that occupies bits 1,6-10,44 of
perf_event_attr::config1.
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index ccd42589e124..ab7d16efa96b 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -70,12 +70,12 @@ show up in /proc/sys/kernel:
- shmall
- shmmax [ sysv ipc ]
- shmmni
-- softlockup_thresh
- stop-a [ SPARC only ]
- sysrq ==> Documentation/sysrq.txt
- tainted
- threads-max
- unknown_nmi_panic
+- watchdog_thresh
- version
==============================================================
@@ -427,6 +427,32 @@ This file shows up if CONFIG_DEBUG_STACKOVERFLOW is enabled.
==============================================================
+perf_cpu_time_max_percent:
+
+Hints to the kernel how much CPU time it should be allowed to
+use to handle perf sampling events. If the perf subsystem
+is informed that its samples are exceeding this limit, it
+will drop its sampling frequency to attempt to reduce its CPU
+usage.
+
+Some perf sampling happens in NMIs. If these samples
+unexpectedly take too long to execute, the NMIs can become
+stacked up next to each other so much that nothing else is
+allowed to execute.
+
+0: disable the mechanism. Do not monitor or correct perf's
+ sampling rate no matter how CPU time it takes.
+
+1-100: attempt to throttle perf's sample rate to this
+ percentage of CPU. Note: the kernel calculates an
+ "expected" length of each sample event. 100 here means
+ 100% of that expected length. Even if this is set to
+ 100, you may still see sample throttling if this
+ length is exceeded. Set to 0 if you truly do not care
+ how much CPU is consumed.
+
+==============================================================
+
pid_max:
@@ -604,15 +630,6 @@ without users and with a dead originative process will be destroyed.
==============================================================
-softlockup_thresh:
-
-This value can be used to lower the softlockup tolerance threshold. The
-default threshold is 60 seconds. If a cpu is locked up for 60 seconds,
-the kernel complains. Valid values are 1-60 seconds. Setting this
-tunable to zero will disable the softlockup detection altogether.
-
-==============================================================
-
tainted:
Non-zero if the kernel has been tainted. Numeric values, which
@@ -648,3 +665,16 @@ that time, kernel debugging information is displayed on console.
NMI switch that most IA32 servers have fires unknown NMI up, for
example. If a system hangs up, try pressing the NMI switch.
+
+==============================================================
+
+watchdog_thresh:
+
+This value can be used to control the frequency of hrtimer and NMI
+events and the soft and hard lockup thresholds. The default threshold
+is 10 seconds.
+
+The softlockup threshold is (2 * watchdog_thresh). Setting this
+tunable to zero will disable lockup detection altogether.
+
+==============================================================
diff --git a/Documentation/trace/events-nmi.txt b/Documentation/trace/events-nmi.txt
new file mode 100644
index 000000000000..c03c8c89f08d
--- /dev/null
+++ b/Documentation/trace/events-nmi.txt
@@ -0,0 +1,43 @@
+NMI Trace Events
+
+These events normally show up here:
+
+ /sys/kernel/debug/tracing/events/nmi
+
+--
+
+nmi_handler:
+
+You might want to use this tracepoint if you suspect that your
+NMI handlers are hogging large amounts of CPU time. The kernel
+will warn if it sees long-running handlers:
+
+ INFO: NMI handler took too long to run: 9.207 msecs
+
+and this tracepoint will allow you to drill down and get some
+more details.
+
+Let's say you suspect that perf_event_nmi_handler() is causing
+you some problems and you only want to trace that handler
+specifically. You need to find its address:
+
+ $ grep perf_event_nmi_handler /proc/kallsyms
+ ffffffff81625600 t perf_event_nmi_handler
+
+Let's also say you are only interested in when that function is
+really hogging a lot of CPU time, like a millisecond at a time.
+Note that the kernel's output is in milliseconds, but the input
+to the filter is in nanoseconds! You can filter on 'delta_ns':
+
+cd /sys/kernel/debug/tracing/events/nmi/nmi_handler
+echo 'handler==0xffffffff81625600 && delta_ns>1000000' > filter
+echo 1 > enable
+
+Your output would then look like:
+
+$ cat /sys/kernel/debug/tracing/trace_pipe
+<idle>-0 [000] d.h3 505.397558: nmi_handler: perf_event_nmi_handler() delta_ns: 3236765 handled: 1
+<idle>-0 [000] d.h3 505.805893: nmi_handler: perf_event_nmi_handler() delta_ns: 3174234 handled: 1
+<idle>-0 [000] d.h3 506.158206: nmi_handler: perf_event_nmi_handler() delta_ns: 3084642 handled: 1
+<idle>-0 [000] d.h3 506.334346: nmi_handler: perf_event_nmi_handler() delta_ns: 3080351 handled: 1
+