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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2016-09-26 02:29:19 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-30 11:46:40 +0200 |
| commit | 68107df5f2cb5dc3785be40162bfe2f19a178bbb (patch) | |
| tree | 12b6a4660458f192213eeac3071c4acb90dbbe63 | |
| parent | 2810f611f908112ea1b30bc016d25205acb3d486 (diff) | |
| download | lwn-68107df5f2cb5dc3785be40162bfe2f19a178bbb.tar.gz lwn-68107df5f2cb5dc3785be40162bfe2f19a178bbb.zip | |
u64_stats: Introduce IRQs disabled helpers
Introduce light versions of u64_stats helpers for context where
either preempt or IRQs are disabled. This way we can make this library
usable by scheduler irqtime accounting which currenty implement its
ad-hoc version.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1474849761-12678-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | include/linux/u64_stats_sync.h | 45 |
1 files changed, 24 insertions, 21 deletions
diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h index d3a2bb712af3..650f3dd6b800 100644 --- a/include/linux/u64_stats_sync.h +++ b/include/linux/u64_stats_sync.h @@ -103,31 +103,42 @@ static inline void u64_stats_update_end_raw(struct u64_stats_sync *syncp) #endif } -static inline unsigned int u64_stats_fetch_begin(const struct u64_stats_sync *syncp) +static inline unsigned int __u64_stats_fetch_begin(const struct u64_stats_sync *syncp) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP) return read_seqcount_begin(&syncp->seq); #else -#if BITS_PER_LONG==32 - preempt_disable(); -#endif return 0; #endif } -static inline bool u64_stats_fetch_retry(const struct u64_stats_sync *syncp, +static inline unsigned int u64_stats_fetch_begin(const struct u64_stats_sync *syncp) +{ +#if BITS_PER_LONG==32 && !defined(CONFIG_SMP) + preempt_disable(); +#endif + return __u64_stats_fetch_begin(syncp); +} + +static inline bool __u64_stats_fetch_retry(const struct u64_stats_sync *syncp, unsigned int start) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP) return read_seqcount_retry(&syncp->seq, start); #else -#if BITS_PER_LONG==32 - preempt_enable(); -#endif return false; #endif } +static inline bool u64_stats_fetch_retry(const struct u64_stats_sync *syncp, + unsigned int start) +{ +#if BITS_PER_LONG==32 && !defined(CONFIG_SMP) + preempt_enable(); +#endif + return __u64_stats_fetch_retry(syncp, start); +} + /* * In case irq handlers can update u64 counters, readers can use following helpers * - SMP 32bit arches use seqcount protection, irq safe. @@ -136,27 +147,19 @@ static inline bool u64_stats_fetch_retry(const struct u64_stats_sync *syncp, */ static inline unsigned int u64_stats_fetch_begin_irq(const struct u64_stats_sync *syncp) { -#if BITS_PER_LONG==32 && defined(CONFIG_SMP) - return read_seqcount_begin(&syncp->seq); -#else -#if BITS_PER_LONG==32 +#if BITS_PER_LONG==32 && !defined(CONFIG_SMP) local_irq_disable(); #endif - return 0; -#endif + return __u64_stats_fetch_begin(syncp); } static inline bool u64_stats_fetch_retry_irq(const struct u64_stats_sync *syncp, - unsigned int start) + unsigned int start) { -#if BITS_PER_LONG==32 && defined(CONFIG_SMP) - return read_seqcount_retry(&syncp->seq, start); -#else -#if BITS_PER_LONG==32 +#if BITS_PER_LONG==32 && !defined(CONFIG_SMP) local_irq_enable(); #endif - return false; -#endif + return __u64_stats_fetch_retry(syncp, start); } #endif /* _LINUX_U64_STATS_SYNC_H */ |