linux/tools/perf/util/bpf_skel/vmlinux
Namhyung Kim 13f35928a4 perf lock contention: Symbolize zone->lock using BTF
The struct zone is embedded in struct pglist_data which can be allocated
for each NUMA node early in the boot process.  As it's not a slab object
nor a global lock, this was not symbolized.

Since the zone->lock is often contended, it'd be nice if we can
symbolize it.  On NUMA systems, node_data array will have pointers for
struct pglist_data.  By following the pointer, it can calculate the
address of each zone and its lock using BTF.  On UMA, it can just use
contig_page_data and its zones.

The following example shows the zone lock contention at the end.

  $ sudo ./perf lock con -abl -E 5 -- ./perf bench sched messaging
  # Running 'sched/messaging' benchmark:
  # 20 sender and receiver processes per group
  # 10 groups == 400 processes run

       Total time: 0.038 [sec]
   contended   total wait     max wait     avg wait            address   symbol

        5167     18.17 ms     10.27 us      3.52 us   ffff953340052d00   &kmem_cache_node (spinlock)
          38     11.75 ms    465.49 us    309.13 us   ffff95334060c480   &sock_inode_cache (spinlock)
        3916     10.13 ms     10.43 us      2.59 us   ffff953342aecb40   &kmem_cache_node (spinlock)
        2963     10.02 ms     13.75 us      3.38 us   ffff9533d2344098   &kmalloc-rnd-08-2k (spinlock)
         216      5.05 ms     99.49 us     23.39 us   ffff9542bf7d65d0   zone_lock (spinlock)

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: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20250401063055.7431-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-04-29 12:23:53 -03:00
..
.gitignore perf tools: Do not ignore the default vmlinux.h 2023-10-18 15:35:20 -07:00
vmlinux.h perf lock contention: Symbolize zone->lock using BTF 2025-04-29 12:23:53 -03:00