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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-20 05:49:41 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-20 05:49:41 +0400
commit8f55cea410dbc56114bb71a3742032070c8108d0 (patch)
tree59605f0ee961274b22f91add33f5c32459471a83 /Documentation
parentb7133a9a103655cda254987a3c0975fd9d8c443f (diff)
parente259514eef764a5286873618e34c560ecb6cff13 (diff)
downloadlinux-8f55cea410dbc56114bb71a3742032070c8108d0.tar.xz
Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf changes from Ingo Molnar: "There are lots of improvements, the biggest changes are: Main kernel side changes: - Improve uprobes performance by adding 'pre-filtering' support, by Oleg Nesterov. - Make some POWER7 events available in sysfs, equivalent to what was done on x86, from Sukadev Bhattiprolu. - tracing updates by Steve Rostedt - mostly misc fixes and smaller improvements. - Use perf/event tracing to report PCI Express advanced errors, by Tony Luck. - Enable northbridge performance counters on AMD family 15h, by Jacob Shin. - This tracing commit: tracing: Remove the extra 4 bytes of padding in events changes the ABI. All involved parties (PowerTop in particular) seem to agree that it's safe to do now with the introduction of libtraceevent, but the devil is in the details ... Main tooling side changes: - Add 'event group view', from Namyung Kim: To use it, 'perf record' should group events when recording. And then perf report parses the saved group relation from file header and prints them together if --group option is provided. You can use the 'perf evlist' command to see event group information: $ perf record -e '{ref-cycles,cycles}' noploop 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ] $ perf evlist --group {ref-cycles,cycles} With this example, default perf report will show you each event separately. You can use --group option to enable event group view: $ perf report --group ... # group: {ref-cycles,cycles} # ======== # Samples: 7K of event 'anon group { ref-cycles, cycles }' # Event count (approx.): 6876107743 # # Overhead Command Shared Object Symbol # ................ ....... ................. .......................... 99.84% 99.76% noploop noploop [.] main 0.07% 0.00% noploop ld-2.15.so [.] strcmp 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del 0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu 0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time 0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask 0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe 0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock 0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page 0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks 0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time As you can see the Overhead column now contains both of ref-cycles and cycles and header line shows group information also - 'anon group { ref-cycles, cycles }'. The output is sorted by period of group leader first. - Initial GTK+ annotate browser, from Namhyung Kim. - Add option for runtime switching perf data file in perf report, just press 's' and a menu with the valid files found in the current directory will be presented, from Feng Tang. - Add support to display whole group data for raw columns, from Jiri Olsa. - Add per processor socket count aggregation in perf stat, from Stephane Eranian. - Add interval printing in 'perf stat', from Stephane Eranian. - 'perf test' improvements - Add support for wildcards in tracepoint system name, from Jiri Olsa. - Add anonymous huge page recognition, from Joshua Zhu. - perf build-id cache now can show DSOs present in a perf.data file that are not in the cache, to integrate with build-id servers being put in place by organizations such as Fedora. - perf top now shares more of the evsel config/creation routines with 'record', paving the way for further integration like 'top' snapshots, etc. - perf top now supports DWARF callchains. - Fix mmap limitations on 32-bit, fix from David Miller. - 'perf bench numa mem' NUMA performance measurement suite - ... and lots of fixes, performance improvements, cleanups and other improvements I failed to list - see the shortlog and git log for details." * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits) perf/x86/amd: Enable northbridge performance counters on AMD family 15h perf/hwbp: Fix cleanup in case of kzalloc failure perf tools: Fix build with bison 2.3 and older. perf tools: Limit unwind support to x86 archs perf annotate: Make it to be able to skip unannotatable symbols perf gtk/annotate: Fail early if it can't annotate perf gtk/annotate: Show source lines with gray color perf gtk/annotate: Support multiple event annotation perf ui/gtk: Implement basic GTK2 annotation browser perf annotate: Fix warning message on a missing vmlinux perf buildid-cache: Add --update option uprobes/perf: Avoid uprobe_apply() whenever possible uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE uprobes/perf: Teach trace_uprobe/perf code to pre-filter uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's uprobes: Introduce uprobe_apply() perf: Introduce hw_perf_event->tp_target and ->tp_list uprobes/perf: Always increment trace_uprobe->nhit uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe uprobes/tracing: Introduce is_trace_uprobe_enabled() ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-event_source-devices-events62
-rw-r--r--Documentation/trace/ftrace.txt83
2 files changed, 145 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
new file mode 100644
index 000000000000..0adeb524c0d4
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
@@ -0,0 +1,62 @@
+What: /sys/devices/cpu/events/
+ /sys/devices/cpu/events/branch-misses
+ /sys/devices/cpu/events/cache-references
+ /sys/devices/cpu/events/cache-misses
+ /sys/devices/cpu/events/stalled-cycles-frontend
+ /sys/devices/cpu/events/branch-instructions
+ /sys/devices/cpu/events/stalled-cycles-backend
+ /sys/devices/cpu/events/instructions
+ /sys/devices/cpu/events/cpu-cycles
+
+Date: 2013/01/08
+
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+
+Description: Generic performance monitoring events
+
+ A collection of performance monitoring events that may be
+ supported by many/most CPUs. These events can be monitored
+ using the 'perf(1)' tool.
+
+ The contents of each file would look like:
+
+ event=0xNNNN
+
+ where 'N' is a hex digit and the number '0xNNNN' shows the
+ "raw code" for the perf event identified by the file's
+ "basename".
+
+
+What: /sys/devices/cpu/events/PM_LD_MISS_L1
+ /sys/devices/cpu/events/PM_LD_REF_L1
+ /sys/devices/cpu/events/PM_CYC
+ /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
+
+Date: 2013/01/08
+
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Linux Powerpc mailing list <linuxppc-dev@ozlabs.org>
+
+Description: POWER-systems specific performance monitoring events
+
+ A collection of performance monitoring events that may be
+ supported by the POWER CPU. These events can be monitored
+ using the 'perf(1)' tool.
+
+ These events may not be supported by other CPUs.
+
+ The contents of each file would look like:
+
+ event=0xNNNN
+
+ where 'N' is a hex digit and the number '0xNNNN' shows the
+ "raw code" for the perf event identified by the file's
+ "basename".
+
+ Further, multiple terms like 'event=0xNNNN' can be specified
+ and separated with comma. All available terms are defined in
+ the /sys/bus/event_source/devices/<dev>/format file.
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 6f51fed45f2d..53d6a3c51d87 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -1842,6 +1842,89 @@ an error.
# cat buffer_size_kb
85
+Snapshot
+--------
+CONFIG_TRACER_SNAPSHOT makes a generic snapshot feature
+available to all non latency tracers. (Latency tracers which
+record max latency, such as "irqsoff" or "wakeup", can't use
+this feature, since those are already using the snapshot
+mechanism internally.)
+
+Snapshot preserves a current trace buffer at a particular point
+in time without stopping tracing. Ftrace swaps the current
+buffer with a spare buffer, and tracing continues in the new
+current (=previous spare) buffer.
+
+The following debugfs files in "tracing" are related to this
+feature:
+
+ snapshot:
+
+ This is used to take a snapshot and to read the output
+ of the snapshot. Echo 1 into this file to allocate a
+ spare buffer and to take a snapshot (swap), then read
+ the snapshot from this file in the same format as
+ "trace" (described above in the section "The File
+ System"). Both reads snapshot and tracing are executable
+ in parallel. When the spare buffer is allocated, echoing
+ 0 frees it, and echoing else (positive) values clear the
+ snapshot contents.
+ More details are shown in the table below.
+
+ status\input | 0 | 1 | else |
+ --------------+------------+------------+------------+
+ not allocated |(do nothing)| alloc+swap | EINVAL |
+ --------------+------------+------------+------------+
+ allocated | free | swap | clear |
+ --------------+------------+------------+------------+
+
+Here is an example of using the snapshot feature.
+
+ # echo 1 > events/sched/enable
+ # echo 1 > snapshot
+ # cat snapshot
+# tracer: nop
+#
+# entries-in-buffer/entries-written: 71/71 #P:8
+#
+# _-----=> irqs-off
+# / _----=> need-resched
+# | / _---=> hardirq/softirq
+# || / _--=> preempt-depth
+# ||| / delay
+# TASK-PID CPU# |||| TIMESTAMP FUNCTION
+# | | | |||| | |
+ <idle>-0 [005] d... 2440.603828: sched_switch: prev_comm=swapper/5 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2242 next_prio=120
+ sleep-2242 [005] d... 2440.603846: sched_switch: prev_comm=snapshot-test-2 prev_pid=2242 prev_prio=120 prev_state=R ==> next_comm=kworker/5:1 next_pid=60 next_prio=120
+[...]
+ <idle>-0 [002] d... 2440.707230: sched_switch: prev_comm=swapper/2 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2229 next_prio=120
+
+ # cat trace
+# tracer: nop
+#
+# entries-in-buffer/entries-written: 77/77 #P:8
+#
+# _-----=> irqs-off
+# / _----=> need-resched
+# | / _---=> hardirq/softirq
+# || / _--=> preempt-depth
+# ||| / delay
+# TASK-PID CPU# |||| TIMESTAMP FUNCTION
+# | | | |||| | |
+ <idle>-0 [007] d... 2440.707395: sched_switch: prev_comm=swapper/7 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2243 next_prio=120
+ snapshot-test-2-2229 [002] d... 2440.707438: sched_switch: prev_comm=snapshot-test-2 prev_pid=2229 prev_prio=120 prev_state=S ==> next_comm=swapper/2 next_pid=0 next_prio=120
+[...]
+
+
+If you try to use this snapshot feature when current tracer is
+one of the latency tracers, you will get the following results.
+
+ # echo wakeup > current_tracer
+ # echo 1 > snapshot
+bash: echo: write error: Device or resource busy
+ # cat snapshot
+cat: snapshot: Device or resource busy
+
-----------
More details can be found in the source code, in the