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| author | Florian Weimer <fweimer@redhat.com> | 2021-12-09 09:49:32 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2021-12-09 09:49:32 +0100 |
| commit | 1d350aa06091211863e41169729cee1bca39f72f (patch) | |
| tree | b091608172a4dd91bf7dfbec91d1ff0aea7d0098 | |
| parent | 95e114a0919d844d8fe07839cb6538b7f5ee920e (diff) | |
| download | glibc-1d350aa06091211863e41169729cee1bca39f72f.tar.gz glibc-1d350aa06091211863e41169729cee1bca39f72f.tar.xz glibc-1d350aa06091211863e41169729cee1bca39f72f.zip | |
Linux: Use rseq to accelerate sched_getcpu
Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
| -rw-r--r-- | sysdeps/unix/sysv/linux/sched_getcpu.c | 19 |
1 files changed, 17 insertions, 2 deletions
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 <sysdep.h> #include <sysdep-vdso.h> -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 */ |