diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2012-02-28 23:46:04 +0400 |
---|---|---|
committer | John Stultz <john.stultz@linaro.org> | 2012-03-16 05:17:58 +0400 |
commit | 2ab516575f2f273b19d95140d02c54612201e80a (patch) | |
tree | 26db92249e65754d99759af21fd207507a81cec8 /arch/x86/vdso/vclock_gettime.c | |
parent | 6c260d586343f7f78239d90aa9e2cfed02f74ff3 (diff) | |
download | linux-2ab516575f2f273b19d95140d02c54612201e80a.tar.xz |
x86: vdso: Use seqcount instead of seqlock
The update of the vdso data happens under xtime_lock, so adding a
nested lock is pointless. Just use a seqcount to sync the readers.
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'arch/x86/vdso/vclock_gettime.c')
-rw-r--r-- | arch/x86/vdso/vclock_gettime.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c index 7eeb1f6188ee..944c5e5d6b6a 100644 --- a/arch/x86/vdso/vclock_gettime.c +++ b/arch/x86/vdso/vclock_gettime.c @@ -100,12 +100,12 @@ notrace static noinline int do_realtime(struct timespec *ts) int mode; do { - seq = read_seqbegin(>od->lock); + seq = read_seqcount_begin(>od->seq); mode = gtod->clock.vclock_mode; ts->tv_sec = gtod->wall_time_sec; ts->tv_nsec = gtod->wall_time_nsec; ns = vgetns(); - } while (unlikely(read_seqretry(>od->lock, seq))); + } while (unlikely(read_seqcount_retry(>od->seq, seq))); timespec_add_ns(ts, ns); return mode; @@ -117,13 +117,13 @@ notrace static noinline int do_monotonic(struct timespec *ts) int mode; do { - seq = read_seqbegin(>od->lock); + seq = read_seqcount_begin(>od->seq); mode = gtod->clock.vclock_mode; secs = gtod->wall_time_sec; ns = gtod->wall_time_nsec + vgetns(); secs += gtod->wall_to_monotonic.tv_sec; ns += gtod->wall_to_monotonic.tv_nsec; - } while (unlikely(read_seqretry(>od->lock, seq))); + } while (unlikely(read_seqcount_retry(>od->seq, seq))); /* wall_time_nsec, vgetns(), and wall_to_monotonic.tv_nsec * are all guaranteed to be nonnegative. @@ -142,10 +142,10 @@ notrace static noinline int do_realtime_coarse(struct timespec *ts) { unsigned long seq; do { - seq = read_seqbegin(>od->lock); + seq = read_seqcount_begin(>od->seq); ts->tv_sec = gtod->wall_time_coarse.tv_sec; ts->tv_nsec = gtod->wall_time_coarse.tv_nsec; - } while (unlikely(read_seqretry(>od->lock, seq))); + } while (unlikely(read_seqcount_retry(>od->seq, seq))); return 0; } @@ -153,12 +153,12 @@ notrace static noinline int do_monotonic_coarse(struct timespec *ts) { unsigned long seq, ns, secs; do { - seq = read_seqbegin(>od->lock); + seq = read_seqcount_begin(>od->seq); secs = gtod->wall_time_coarse.tv_sec; ns = gtod->wall_time_coarse.tv_nsec; secs += gtod->wall_to_monotonic.tv_sec; ns += gtod->wall_to_monotonic.tv_nsec; - } while (unlikely(read_seqretry(>od->lock, seq))); + } while (unlikely(read_seqcount_retry(>od->seq, seq))); /* wall_time_nsec and wall_to_monotonic.tv_nsec are * guaranteed to be between 0 and NSEC_PER_SEC. |