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Author SHA1 Message Date
Namhyung Kim
5e3febe7b7 perf lock contention: Support lock addr/name filtering for BPF
Likewise, add addr_filter BPF hash map and check it with the lock
address.

  $ sudo ./perf lock con -ab -L tasklist_lock -- ./perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.169 [sec]
   contended  total wait  max wait  avg wait      type  caller

          18   174.09 us  25.31 us   9.67 us  rwlock:W  do_exit+0x36d
           5    32.34 us  10.87 us   6.47 us  rwlock:R  do_wait+0x8b
           4    15.41 us   4.73 us   3.85 us  rwlock:W  release_task+0x6e

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221219201732.460111-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-21 14:52:39 -03:00
Namhyung Kim
529772c4df perf lock contention: Support lock type filtering for BPF
Likewise, add type_filter BPF hash map and check it when user gave a
lock type filter.

  $ sudo ./perf lock con -ab -Y rwlock -- ./perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.203 [sec]
   contended  total wait  max wait  avg wait       type  caller

          15   156.19 us  19.45 us  10.41 us   rwlock:W  do_exit+0x36d
           1    11.12 us  11.12 us  11.12 us   rwlock:R  do_wait+0x8b
           1     5.09 us   5.09 us   5.09 us   rwlock:W  release_task+0x6e

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221219201732.460111-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-21 14:52:39 -03:00
Yang Jihong
7c0a6144f9 perf tools: Fix usage of the verbose variable
The data type of the verbose variable is integer and can be negative,
replace improperly used cases in a unified manner:
 1. if (verbose)        => if (verbose > 0)
 2. if (!verbose)       => if (verbose <= 0)
 3. if (XX && verbose)  => if (XX && verbose > 0)
 4. if (XX && !verbose) => if (XX && verbose <= 0)

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20221220035702.188413-3-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-20 15:16:33 -03:00
Namhyung Kim
688d2e8de2 perf lock contention: Add -l/--lock-addr option
The -l/--lock-addr option is to implement per-lock-instance contention
stat using LOCK_AGGR_ADDR.  It displays lock address and optionally
symbol name if exists.

  $ sudo ./perf lock con -abl sleep 1
   contended   total wait     max wait     avg wait            address   symbol

           1     36.28 us     36.28 us     36.28 us   ffff92615d6448b8
           9     10.91 us      1.84 us      1.21 us   ffffffffbaed50c0   rcu_state
           1     10.49 us     10.49 us     10.49 us   ffff9262ac4f0c80
           8      4.68 us      1.67 us       585 ns   ffffffffbae07a40   jiffies_lock
           3      3.03 us      1.45 us      1.01 us   ffff9262277861e0
           1       924 ns       924 ns       924 ns   ffff926095ba9d20
           1       436 ns       436 ns       436 ns   ffff9260bfda4f60

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221209190727.759804-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-14 11:24:31 -03:00
Namhyung Kim
eca949b2b4 perf lock contention: Implement -t/--threads option for BPF
The BPF didn't show the per-thread stat properly.  Use task's thread id (PID)
as a key instead of stack_id and add a task_data map to save task comm names.

  $ sudo ./perf lock con -abt -E 5 sleep 1
   contended   total wait     max wait     avg wait          pid   comm

           1    740.66 ms    740.66 ms    740.66 ms         1950   nv_queue
           3    305.50 ms    298.19 ms    101.83 ms         1884   nvidia-modeset/
           1     25.14 us     25.14 us     25.14 us      2725038   EventManager_De
          12     23.09 us      9.30 us      1.92 us            0   swapper
           1     20.18 us     20.18 us     20.18 us      2725033   EventManager_De

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221209190727.759804-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-14 11:24:31 -03:00
Namhyung Kim
fd507d3e35 perf lock contention: Add lock_data.h for common data
Accessing BPF maps should use the same data types.  Add bpf_skel/lock_data.h
to define the common data structures.  No functional changes.

Committer notes:

Fixed contention_key.stack_id missing rename to contention_key.stack_or_task_id.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221209190727.759804-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-14 11:24:31 -03:00
Arnaldo Carvalho de Melo
cc2367eebb machine: Adopt is_lock_function() from builtin-lock.c
It is used in bpf_lock_contention.c and builtin-lock.c will be made
CONFIG_LIBTRACEEVENT=y conditional, so move it to machine.c, that is
always available.

This makes those 4 global variables for sched and lock text start and
end to move to 'struct machine' too, as conceivably we can have that
info for several machine instances, say some 'perf diff' like tool.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-12-14 11:16:12 -03:00
Namhyung Kim
c66a36af7b perf lock contention: Do not use BPF task local storage
It caused some troubles when a lock inside kmalloc is contended
because task local storage would allocate memory using kmalloc.
It'd create a recusion and even crash in my system.

There could be a couple of workarounds but I think the simplest
one is to use a pre-allocated hash map.  We could fix the task
local storage to use the safe BPF allocator, but it takes time
so let's change this until it happens actually.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chris Li <chriscli@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221118190109.1512674-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-23 10:42:28 -03:00
Namhyung Kim
9e9c5f3cf9 perf lock contention: Avoid variable length arrays
The msan also warns about the use of VLA for stack_trace variable.
We can dynamically allocate instead.  While at it, simplify the error
handle a bit (and fix bugs).

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221028180128.3311491-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-31 11:07:45 -03:00
Namhyung Kim
005ef2b41b perf lock contention: Fix memory sanitizer issue
The msan reported a use-of-uninitialized-value warning for the struct
lock_contention_data in lock_contention_read().  While it'd be filled
by bpf_map_lookup_elem(), let's just initialize it to silence the
warning.

  ==12524==WARNING: MemorySanitizer: use-of-uninitialized-value
  #0 0x562b0f16b1cd in lock_contention_read  util/bpf_lock_contention.c:139:7
  #1 0x562b0ef65ec6 in __cmd_contention  builtin-lock.c:1737:3
  #2 0x562b0ef65ec6 in cmd_lock  builtin-lock.c:1992:8
  #3 0x562b0ee7f50b in run_builtin  perf.c:322:11
  #4 0x562b0ee7efc1 in handle_internal_command  perf.c:376:8
  #5 0x562b0ee7e1e9 in run_argv  perf.c:420:2
  #6 0x562b0ee7e1e9 in main  perf.c:550:3
  #7 0x7f065f10e632 in __libc_start_main (/usr/lib64/libc.so.6+0x61632)
  #8 0x562b0edf2fa9 in _start (perf+0xfa9)
  SUMMARY: MemorySanitizer: use-of-uninitialized-value (perf+0xe15160) in lock_contention_read

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221028180128.3311491-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-31 11:07:29 -03:00
Yuan Can
20b2194eee perf lock: Remove unused struct lock_contention_key
The struct lock_contention_key is never used, remove it.

Signed-off-by: Yuan Can <yuancan@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/linux-perf-users/20220927013931.110475-6-yuancan@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-06 08:03:52 -03:00
Namhyung Kim
c1da8dd5c1 perf lock contention: Skip stack trace from BPF
Currently it collects stack traces to max size then skip entries.
Because we don't have control how to skip perf callchains.  But BPF can
do it with bpf_get_stackid() with a flag.

Say we have max-stack=4 and stack-skip=2, we get these stack traces.

Before:                    After:

     .---> +---+ <--.           .---> +---+ <--.
     |     |   |    |           |     |   |    |
     |     +---+  usable        |     +---+    |
    max    |   |    |          max    |   |    |
   stack   +---+ <--'         stack   +---+  usable
     |     | X |                |     |   |    |
     |     +---+   skip         |     +---+    |
     |     | X |                |     |   |    |
     `---> +---+                `---> +---+ <--'   <=== collection
                                      | X |
                                      +---+   skip
                                      | X |
                                      +---+

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220912055314.744552-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-04 08:55:22 -03:00
Namhyung Kim
96532a83ee perf lock contention: Allow to change stack depth and skip
It needs stack traces to find callers of locks.  To minimize the
performance overhead it only collects up to 8 entries for each stack
trace.  And it skips first 3 entries as they came from BPF, tracepoint
and lock functions which are not interested for most users.

But it turned out that those numbers are different in some
configuration.  Using fixed number can result in non meaningful caller
names.  Let's make them adjustable with --stack-depth and --skip-stack
options.

On my setup, the default output is like below:

  # /perf lock con -ab -F contended,wait_total sleep 3
   contended   total wait         type   caller

          28      4.55 ms     rwlock:W   __bpf_trace_contention_begin+0xb
          33      1.67 ms     rwlock:W   __bpf_trace_contention_begin+0xb
          12    580.28 us     spinlock   __bpf_trace_contention_begin+0xb
          60    240.54 us      rwsem:R   __bpf_trace_contention_begin+0xb
          27     64.45 us     spinlock   __bpf_trace_contention_begin+0xb

If I change the stack skip to 5, the result will be like:

  # perf lock con -ab -F contended,wait_total --stack-skip 5 sleep 3
   contended   total wait         type   caller

          32    715.45 us     spinlock   folio_lruvec_lock_irqsave+0x61
          26    550.22 us     spinlock   folio_lruvec_lock_irqsave+0x61
          15    486.93 us      rwsem:R   mmap_read_lock+0x13
          12    139.66 us      rwsem:W   vm_mmap_pgoff+0x93
           1      7.04 us     spinlock   tick_do_update_jiffies64+0x25

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220912055314.744552-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-04 08:55:22 -03:00
Namhyung Kim
a6eaf966bc perf lock contention: Show full callstack with -v option
Currently it shows a caller function for each entry, but users need to see
the full call stacks sometimes.  Use -v/--verbose option to do that.

  # perf lock con -a -b -v sleep 3
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: cannot get elf header.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
   contended   total wait     max wait     avg wait         type   caller

           1     10.74 us     10.74 us     10.74 us     spinlock   __bpf_trace_contention_begin+0xb
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffbb8b8e75  bpf_trace_run2+0x35
                          0xffffffffbb7eab9b  __bpf_trace_contention_begin+0xb
                          0xffffffffbb7ebe75  queued_spin_lock_slowpath+0x1f5
                          0xffffffffbc1c26ff  _raw_spin_lock+0x1f
                          0xffffffffbb841015  tick_do_update_jiffies64+0x25
                          0xffffffffbb8409ee  tick_irq_enter+0x9e
           1      7.70 us      7.70 us      7.70 us     spinlock   __bpf_trace_contention_begin+0xb
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffc03b5c47  bpf_prog_bf07ae9e2cbd02c5_contention_begin+0x117
                          0xffffffffbb8b8e75  bpf_trace_run2+0x35
                          0xffffffffbb7eab9b  __bpf_trace_contention_begin+0xb
                          0xffffffffbb7ebe75  queued_spin_lock_slowpath+0x1f5
                          0xffffffffbc1c26ff  _raw_spin_lock+0x1f
                          0xffffffffbb7bc27e  raw_spin_rq_lock_nested+0xe
                          0xffffffffbb7cef9c  load_balance+0x66c

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220912055314.744552-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-10-04 08:55:22 -03:00
Namhyung Kim
6d499a6b3d perf lock: Print the number of lost entries for BPF
Like the normal 'perf lock contention' output, it'd print the number of
lost entries for BPF if exists or -v option is passed.

Currently it uses BROKEN_CONTENDED stat for the lost count (due to full
stack maps).

  $ sudo perf lock con -a -b --map-nr-entries 128 sleep 5
  ...
  === output for debug===

  bad: 43, total: 14903
  bad rate: 0.29 %
  histogram of events caused bad sequence
      acquire: 0
     acquired: 0
    contended: 43
      release: 0

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220802191004.347740-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-02 18:03:31 -03:00
Namhyung Kim
ceb13bfc01 perf lock: Add --map-nr-entries option
The --map-nr-entries option is to control number of max entries in the
perf lock contention BPF maps.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220802191004.347740-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-02 18:02:59 -03:00
Namhyung Kim
447ec4e5fa perf lock: Introduce struct lock_contention
The lock_contention struct is to carry related fields together and to
minimize the change when we add new config options.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220802191004.347740-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-02 18:02:10 -03:00
Namhyung Kim
6fda2405f4 perf lock: Implement cpu and task filters for BPF
Add -a/--all-cpus and -C/--cpu options for cpu filtering.  Also -p/--pid
and --tid options are added for task filtering.  The short -t option is
taken for --threads already.  Tracking the command line workload is
possible as well.

  $ sudo perf lock contention -a -b sleep 1

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220729200756.666106-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-01 09:28:51 -03:00
Namhyung Kim
407b36f69e perf lock: Use BPF for lock contention analysis
Add -b/--use-bpf option to use BPF to collect lock contention stats.
For simplicity it now runs system-wide and requires C-c to stop.
Upcoming changes will add the usual filtering.

  $ sudo perf lock con -b
  ^C
   contended   total wait     max wait     avg wait         type   caller

          42    192.67 us     13.64 us      4.59 us     spinlock   queue_work_on+0x20
          23     85.54 us     10.28 us      3.72 us     spinlock   worker_thread+0x14a
           6     13.92 us      6.51 us      2.32 us        mutex   kernfs_iop_permission+0x30
           3     11.59 us     10.04 us      3.86 us        mutex   kernfs_dop_revalidate+0x3c
           1      7.52 us      7.52 us      7.52 us     spinlock   kthread+0x115
           1      7.24 us      7.24 us      7.24 us     rwlock:W   sys_epoll_wait+0x148
           2      7.08 us      3.99 us      3.54 us     spinlock   delayed_work_timer_fn+0x1b
           1      6.41 us      6.41 us      6.41 us     spinlock   idle_balance+0xa06
           2      2.50 us      1.83 us      1.25 us        mutex   kernfs_iop_lookup+0x2f
           1      1.71 us      1.71 us      1.71 us        mutex   kernfs_iop_getattr+0x2c

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220729200756.666106-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-01 09:28:38 -03:00