x86-64: Optimize vDSO time()

[platform/adaptation/renesas_rcar/renesas_kernel.git] / arch / x86 / vdso / vclock_gettime.c

diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index e6e9f90..a69929e 100644 (file)
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -180,12 +180,8 @@ notrace time_t __vdso_time(time_t *t)
        if (unlikely(!VVAR(vsyscall_gtod_data).sysctl_enabled))
                return time_syscall(t);
 
-       do {
-               seq = read_seqbegin(&VVAR(vsyscall_gtod_data).lock);
-
-               result = VVAR(vsyscall_gtod_data).wall_time_sec;
-
-       } while (read_seqretry(&VVAR(vsyscall_gtod_data).lock, seq));
+       /* This is atomic on x86_64 so we don't need any locks. */
+       result = ACCESS_ONCE(VVAR(vsyscall_gtod_data).wall_time_sec);
 
        if (t)
                *t = result;