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
memweight.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/bug.h>
#include <linux/bitmap.h>
/**
* memweight - count the total number of bits set in memory area
* @ptr: pointer to the start of the area
* @bytes: the size of the area
*/
size_t memweight(const void *ptr, size_t bytes)
{
size_t ret = 0;
size_t longs;
const unsigned char *bitmap = ptr;
for (; bytes > 0 && ((unsigned long)bitmap) % sizeof(long);
bytes--, bitmap++)
ret += hweight8(*bitmap);
longs = bytes / sizeof(long);
if (longs) {
BUG_ON(longs >= INT_MAX / BITS_PER_LONG);
ret += bitmap_weight((unsigned long *)bitmap,
longs * BITS_PER_LONG);
bytes -= longs * sizeof(long);
bitmap += longs * sizeof(long);
}
/*
* The reason that this last loop is distinct from the preceding
* bitmap_weight() call is to compute 1-bits in the last region smaller
* than sizeof(long) properly on big-endian systems.
*/
for (; bytes > 0; bytes--, bitmap++)
ret += hweight8(*bitmap);
return ret;
}
EXPORT_SYMBOL(memweight);
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