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| author |   Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-04-16 18:29:19 +0200 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2025-05-03 12:02:10 +0200 |
| commit | 60035a3981a7f9d965df81a48a07b94e52ccd54f (patch) | |
| tree | ba73a5f5e01b367a87b8208b851923908660a96a /tools/perf/bench/futex.h | |
| parent | tools headers: Synchronize prctl.h ABI header (diff) | |
| download | wireguard-linux-60035a3981a7f9d965df81a48a07b94e52ccd54f.tar.xz wireguard-linux-60035a3981a7f9d965df81a48a07b94e52ccd54f.zip | |
tools/perf: Allow to select the number of hash buckets
Add the -b/ --buckets argument to specify the number of hash buckets for
the private futex hash. This is directly passed to
prctl(PR_FUTEX_HASH, PR_FUTEX_HASH_SET_SLOTS, buckets, immutable)
and must return without an error if specified. The `immutable' is 0 by
default and can be set to 1 via the -I/ --immutable argument.
The size of the private hash is verified with PR_FUTEX_HASH_GET_SLOTS.
If PR_FUTEX_HASH_GET_SLOTS failed then it is assumed that an older
kernel was used without the support and that the global hash is used.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250416162921.513656-20-bigeasy@linutronix.de
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/bench/futex.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h index ebdc2b032afc..9c9a73f9d865 100644 --- a/tools/perf/bench/futex.h +++ b/tools/perf/bench/futex.h @@ -25,6 +25,8 @@ struct bench_futex_parameters { unsigned int nfutexes; unsigned int nwakes; unsigned int nrequeue; + int nbuckets; + bool buckets_immutable; }; /** @@ -143,4 +145,7 @@ futex_cmp_requeue_pi(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, val, opflags); } +void futex_set_nbuckets_param(struct bench_futex_parameters *params); +void futex_print_nbuckets(struct bench_futex_parameters *params); + #endif /* _FUTEX_H */ |