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| author | Thomas Gleixner <tglx@linutronix.de> | 2012-02-28 19:46:05 +0000 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2012-03-15 18:17:59 -0700 |
| commit | 74a622be3db2898251cb524d1edbeaea589f2723 (patch) | |
| tree | d54a6960bedd0176d7ff1f7dc3092df42d1917bd | |
| parent | 2ab516575f2f273b19d95140d02c54612201e80a (diff) | |
| download | talos-obmc-linux-74a622be3db2898251cb524d1edbeaea589f2723.tar.gz talos-obmc-linux-74a622be3db2898251cb524d1edbeaea589f2723.zip | |
ia64: vsyscall: 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.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
| -rw-r--r-- | arch/ia64/kernel/asm-offsets.c | 4 | ||||
| -rw-r--r-- | arch/ia64/kernel/fsys.S | 2 | ||||
| -rw-r--r-- | arch/ia64/kernel/fsyscall_gtod_data.h | 2 | ||||
| -rw-r--r-- | arch/ia64/kernel/time.c | 10 |
4 files changed, 7 insertions, 11 deletions
diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c index af5650169043..106aeb670e54 100644 --- a/arch/ia64/kernel/asm-offsets.c +++ b/arch/ia64/kernel/asm-offsets.c @@ -269,8 +269,8 @@ void foo(void) BLANK(); /* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */ - DEFINE(IA64_GTOD_LOCK_OFFSET, - offsetof (struct fsyscall_gtod_data_t, lock)); + DEFINE(IA64_GTOD_SEQ_OFFSET, + offsetof (struct fsyscall_gtod_data_t, seq); DEFINE(IA64_GTOD_WALL_TIME_OFFSET, offsetof (struct fsyscall_gtod_data_t, wall_time)); DEFINE(IA64_GTOD_MONO_TIME_OFFSET, diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S index 331d42bda77a..fa77de7032b3 100644 --- a/arch/ia64/kernel/fsys.S +++ b/arch/ia64/kernel/fsys.S @@ -174,7 +174,7 @@ ENTRY(fsys_set_tid_address) FSYS_RETURN END(fsys_set_tid_address) -#if IA64_GTOD_LOCK_OFFSET !=0 +#if IA64_GTOD_SEQ_OFFSET !=0 #error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t #endif #if IA64_ITC_JITTER_OFFSET !=0 diff --git a/arch/ia64/kernel/fsyscall_gtod_data.h b/arch/ia64/kernel/fsyscall_gtod_data.h index 57d2ee6c83e1..146b15b5fec3 100644 --- a/arch/ia64/kernel/fsyscall_gtod_data.h +++ b/arch/ia64/kernel/fsyscall_gtod_data.h @@ -6,7 +6,7 @@ */ struct fsyscall_gtod_data_t { - seqlock_t lock; + seqcount_t seq; struct timespec wall_time; struct timespec monotonic_time; cycle_t clk_mask; diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 43920de425f1..8e991a0b5e35 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -35,9 +35,7 @@ static cycle_t itc_get_cycles(struct clocksource *cs); -struct fsyscall_gtod_data_t fsyscall_gtod_data = { - .lock = __SEQLOCK_UNLOCKED(fsyscall_gtod_data.lock), -}; +struct fsyscall_gtod_data_t fsyscall_gtod_data; struct itc_jitter_data_t itc_jitter_data; @@ -460,9 +458,7 @@ void update_vsyscall_tz(void) void update_vsyscall(struct timespec *wall, struct timespec *wtm, struct clocksource *c, u32 mult) { - unsigned long flags; - - write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags); + write_seqcount_begin(&fsyscall_gtod_data.seq); /* copy fsyscall clock data */ fsyscall_gtod_data.clk_mask = c->mask; @@ -485,6 +481,6 @@ void update_vsyscall(struct timespec *wall, struct timespec *wtm, fsyscall_gtod_data.monotonic_time.tv_sec++; } - write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags); + write_seqcount_end(&fsyscall_gtod_data.seq); } |
