[PATCHSET 0/6] perf lock: Random updates for the locking analysis (v2)

[Namhyung Kim]

Hello,

I have some updates in the perf lock command (focused on 'report').
The main change is to add -c (or --combine-locks) option to aggregate
results based on lock class name.

 * changes from v1)
  - rebased onto recent acme/perf/core
  - add Jiri's Acked-by

Without this option, the result deals with lock addresses so instances
in the same lock class will have separate entries like below:

  # perf lock report
                  Name   acquired  contended   avg wait (ns) total wait (ns)   max wait (ns)   min wait (ns) 

         rcu_read_lock     251225          0               0               0               0               0 
   &(ei->i_block_re...       8731          0               0               0               0               0 
   &sb->s_type->i_l...       8731          0               0               0               0               0 
   hrtimer_bases.lo...       5261          0               0               0               0               0 
   hrtimer_bases.lo...       2626          0               0               0               0               0 
   hrtimer_bases.lo...       1953          0               0               0               0               0 
   hrtimer_bases.lo...       1382          0               0               0               0               0 
   cpu_hotplug_lock...       1350          0               0               0               0               0 
   hrtimer_bases.lo...       1273          0               0               0               0               0 
   hrtimer_bases.lo...       1269          0               0               0               0               0 
   hrtimer_bases.lo...       1198          0               0               0               0               0 
   hrtimer_bases.lo...       1116          0               0               0               0               0 
           &base->lock       1109          0               0               0               0               0 
   hrtimer_bases.lo...       1067          0               0               0               0               0 
   hrtimer_bases.lo...       1052          0               0               0               0               0 
   hrtimer_bases.lo...        957          0               0               0               0               0 
   hrtimer_bases.lo...        948          0               0               0               0               0 
          css_set_lock        791          0               0               0               0               0 
   hrtimer_bases.lo...        752          0               0               0               0               0 
   &lruvec->lru_loc...        747          5           11254           56272           18317            1412 
   hrtimer_bases.lo...        738          0               0               0               0               0 
   &newf->file_lock...        706         15            1025           15388            2279             618 
   hrtimer_bases.lo...        702          0               0               0               0               0 
   hrtimer_bases.lo...        694          0               0               0               0               0 
  ...

With -c option, the hrtimer_bases.lock would be combined into a single
entry.  Also note that the lock names are correctly displayed now.

  # perf lock report -c
                  Name   acquired  contended   avg wait (ns) total wait (ns)   max wait (ns)   min wait (ns) 
  
         rcu_read_lock     251225          0               0               0               0               0 
    hrtimer_bases.lock      39449          0               0               0               0               0 
   &sb->s_type->i_l...      10301          1             662             662             662             662 
      ptlock_ptr(page)      10173          2             701            1402             760             642 
   &(ei->i_block_re...       8732          0               0               0               0               0 
           &base->lock       6705          0               0               0               0               0 
           &p->pi_lock       5549          0               0               0               0               0 
   &dentry->d_lockr...       5010          4            1274            5097            1844             789 
             &ep->lock       2750          0               0               0               0               0 
   &(__futex_data.q...       2331          0               0               0               0               0 
                (null)       1878          0               0               0               0               0 
      cpu_hotplug_lock       1350          0               0               0               0               0 
      &____s->seqcount       1349          0               0               0               0               0 
      &newf->file_lock       1001         15            1025           15388            2279             618 
  ...

Maybe we can make it default later (with a config and --no-combine-locks).

You can get it from 'perf/lock-combine-v2' branch at

  git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git

Thanks,
Namhyung


Namhyung Kim (6):
  perf lock: Convert lockhash_table to use hlist
  perf lock: Change type of lock_stat->addr to u64
  perf lock: Sort map info based on class name
  perf lock: Fix lock name length check for printing
  perf lock: Add -c/--combine-locks option
  perf lock: Carefully combine lock stats for discarded entries

 tools/perf/Documentation/perf-lock.txt |   4 +
 tools/perf/builtin-lock.c              | 155 +++++++++++++++++++------
 2 files changed, 124 insertions(+), 35 deletions(-)


base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07
-- 
2.35.0.rc0.227.g00780c9af4-goog