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authorThomas Gleixner <tglx@linutronix.de>2012-02-28 19:46:04 +0000
committerJohn Stultz <john.stultz@linaro.org>2012-03-15 18:17:58 -0700
commit2ab516575f2f273b19d95140d02c54612201e80a (patch)
tree26db92249e65754d99759af21fd207507a81cec8 /arch/x86/vdso
parent6c260d586343f7f78239d90aa9e2cfed02f74ff3 (diff)
downloadop-kernel-dev-2ab516575f2f273b19d95140d02c54612201e80a.zip
op-kernel-dev-2ab516575f2f273b19d95140d02c54612201e80a.tar.gz
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')
-rw-r--r--arch/x86/vdso/vclock_gettime.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index 7eeb1f6..944c5e5 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(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->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(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->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(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->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(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->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(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->seq);
ts->tv_sec = gtod->wall_time_coarse.tv_sec;
ts->tv_nsec = gtod->wall_time_coarse.tv_nsec;
- } while (unlikely(read_seqretry(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->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(&gtod->lock);
+ seq = read_seqcount_begin(&gtod->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(&gtod->lock, seq)));
+ } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
/* wall_time_nsec and wall_to_monotonic.tv_nsec are
* guaranteed to be between 0 and NSEC_PER_SEC.
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