Revision 511e19b9e2112463c33a744ecb8a798056074408 authored by Namhyung Kim on 19 December 2022, 20:17:30 UTC, committed by Arnaldo Carvalho de Melo on 21 December 2022, 17:52:39 UTC
The -L/--lock-filter option is to filter only given locks.  The locks
can be specified by address or name (if exists).

  $ sudo ./perf lock record -a  sleep 1

  $ sudo ./perf lock con -l
   contended  total wait  max wait  avg wait           address  symbol

          57     1.11 ms  42.83 us  19.54 us  ffff9f4140059000
          15   280.88 us  23.51 us  18.73 us  ffffffff9d007a40  jiffies_lock
           1    20.49 us  20.49 us  20.49 us  ffffffff9d0d50c0  rcu_state
           1     9.02 us   9.02 us   9.02 us  ffff9f41759e9ba0

  $ sudo ./perf lock con -L jiffies_lock,rcu_state
   contended  total wait  max wait  avg wait      type  caller

          15   280.88 us  23.51 us  18.73 us  spinlock  tick_sched_do_timer+0x93
           1    20.49 us  20.49 us  20.49 us  spinlock  __softirqentry_text_start+0xeb

  $ sudo ./perf lock con -L ffff9f4140059000
   contended  total wait  max wait  avg wait      type  caller

          38   779.40 us  42.83 us  20.51 us  spinlock  worker_thread+0x50
          11   216.30 us  39.87 us  19.66 us  spinlock  queue_work_on+0x39
           8   118.13 us  20.51 us  14.77 us  spinlock  kthread+0xe5

Committer testing:

  # uname -a
  Linux quaco 6.0.12-200.fc36.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Dec 8 17:15:53 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
  # perf lock record
  ^C[ perf record: Woken up 1 times to write data ]
  # perf lock con -L jiffies_lock,rcu_state
   contended   total wait     max wait     avg wait         type   caller

  # perf lock con
   contended   total wait     max wait     avg wait         type   caller

           1      9.06 us      9.06 us      9.06 us     spinlock   call_timer_fn+0x24
  # perf lock con -L call
  ignore unknown symbol: call
   contended   total wait     max wait     avg wait         type   caller

           1      9.06 us      9.06 us      9.06 us     spinlock   call_timer_fn+0x24
  #

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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/20221219201732.460111-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 parent 529772c
Raw File
bucket_locks.c
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

/* Allocate an array of spinlocks to be accessed by a hash. Two arguments
 * indicate the number of elements to allocate in the array. max_size
 * gives the maximum number of elements to allocate. cpu_mult gives
 * the number of locks per CPU to allocate. The size is rounded up
 * to a power of 2 to be suitable as a hash table.
 */

int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
			     size_t max_size, unsigned int cpu_mult, gfp_t gfp,
			     const char *name, struct lock_class_key *key)
{
	spinlock_t *tlocks = NULL;
	unsigned int i, size;
#if defined(CONFIG_PROVE_LOCKING)
	unsigned int nr_pcpus = 2;
#else
	unsigned int nr_pcpus = num_possible_cpus();
#endif

	if (cpu_mult) {
		nr_pcpus = min_t(unsigned int, nr_pcpus, 64UL);
		size = min_t(unsigned int, nr_pcpus * cpu_mult, max_size);
	} else {
		size = max_size;
	}

	if (sizeof(spinlock_t) != 0) {
		tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp);
		if (!tlocks)
			return -ENOMEM;
		for (i = 0; i < size; i++) {
			spin_lock_init(&tlocks[i]);
			lockdep_init_map(&tlocks[i].dep_map, name, key, 0);
		}
	}

	*locks = tlocks;
	*locks_mask = size - 1;

	return 0;
}
EXPORT_SYMBOL(__alloc_bucket_spinlocks);

void free_bucket_spinlocks(spinlock_t *locks)
{
	kvfree(locks);
}
EXPORT_SYMBOL(free_bucket_spinlocks);
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