diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-02-28 19:46:04 +0000 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2012-03-15 18:17:58 -0700 |
| commit | 2ab516575f2f273b19d95140d02c54612201e80a (patch) | |
| tree | 26db92249e65754d99759af21fd207507a81cec8 /arch/x86/kernel/vsyscall_64.c | |
| parent | 6c260d586343f7f78239d90aa9e2cfed02f74ff3 (diff) | |
| download | talos-obmc-linux-2ab516575f2f273b19d95140d02c54612201e80a.tar.gz talos-obmc-linux-2ab516575f2f273b19d95140d02c54612201e80a.zip | |
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/kernel/vsyscall_64.c')
| -rw-r--r-- | arch/x86/kernel/vsyscall_64.c | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 33385c18e5d3..cdc95a707cd1 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -52,10 +52,7 @@ #include "vsyscall_trace.h" DEFINE_VVAR(int, vgetcpu_mode); -DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) = -{ - .lock = __SEQLOCK_UNLOCKED(__vsyscall_gtod_data.lock), -}; +DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data); static enum { EMULATE, NATIVE, NONE } vsyscall_mode = EMULATE; @@ -86,9 +83,7 @@ void update_vsyscall_tz(void) void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, struct clocksource *clock, u32 mult) { - unsigned long flags; - - write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags); + write_seqcount_begin(&vsyscall_gtod_data.seq); /* copy vsyscall data */ vsyscall_gtod_data.clock.vclock_mode = clock->archdata.vclock_mode; @@ -101,7 +96,7 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, vsyscall_gtod_data.wall_to_monotonic = *wtm; vsyscall_gtod_data.wall_time_coarse = __current_kernel_time(); - write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); + write_seqcount_end(&vsyscall_gtod_data.seq); } static void warn_bad_vsyscall(const char *level, struct pt_regs *regs, |
