From 1d350aa06091211863e41169729cee1bca39f72f Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 9 Dec 2021 09:49:32 +0100 Subject: Linux: Use rseq to accelerate sched_getcpu Co-Authored-By: Mathieu Desnoyers Reviewed-by: Szabolcs Nagy --- sysdeps/unix/sysv/linux/sched_getcpu.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/unix/sysv/linux/sched_getcpu.c b/sysdeps/unix/sysv/linux/sched_getcpu.c index c41e986f2c..6f78edaea1 100644 --- a/sysdeps/unix/sysv/linux/sched_getcpu.c +++ b/sysdeps/unix/sysv/linux/sched_getcpu.c @@ -20,8 +20,8 @@ #include #include -int -sched_getcpu (void) +static int +vsyscall_sched_getcpu (void) { unsigned int cpu; int r = -1; @@ -32,3 +32,18 @@ sched_getcpu (void) #endif return r == -1 ? r : cpu; } + +#ifdef RSEQ_SIG +int +sched_getcpu (void) +{ + int cpu_id = THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id); + return __glibc_likely (cpu_id >= 0) ? cpu_id : vsyscall_sched_getcpu (); +} +#else /* RSEQ_SIG */ +int +sched_getcpu (void) +{ + return vsyscall_sched_getcpu (); +} +#endif /* RSEQ_SIG */ -- cgit v1.2.3