diff options
| author | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:36:13 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:36:13 +0200 |
| commit | 37bf06375c90a42fe07b9bebdb07bc316ae5a0ce (patch) | |
| tree | de572dd6d3955b0725001776a7b03796f99e1e8e /drivers/md/dm-stats.c | |
| parent | sched/rt: Remove redundant nr_cpus_allowed test (diff) | |
| parent | Linux 3.12-rc4 (diff) | |
| download | linux-37bf06375c90a42fe07b9bebdb07bc316ae5a0ce.tar.xz linux-37bf06375c90a42fe07b9bebdb07bc316ae5a0ce.zip | |
Merge tag 'v3.12-rc4' into sched/core
Merge Linux v3.12-rc4 to fix a conflict and also to refresh the tree
before applying more scheduler patches.
Conflicts:
arch/avr32/include/asm/Kbuild
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/md/dm-stats.c')
| -rw-r--r-- | drivers/md/dm-stats.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index 8ae31e8d3d64..3d404c1371ed 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -451,19 +451,26 @@ static void dm_stat_for_entry(struct dm_stat *s, size_t entry, struct dm_stat_percpu *p; /* - * For strict correctness we should use local_irq_disable/enable + * For strict correctness we should use local_irq_save/restore * instead of preempt_disable/enable. * - * This is racy if the driver finishes bios from non-interrupt - * context as well as from interrupt context or from more different - * interrupts. + * preempt_disable/enable is racy if the driver finishes bios + * from non-interrupt context as well as from interrupt context + * or from more different interrupts. * - * However, the race only results in not counting some events, - * so it is acceptable. + * On 64-bit architectures the race only results in not counting some + * events, so it is acceptable. On 32-bit architectures the race could + * cause the counter going off by 2^32, so we need to do proper locking + * there. * * part_stat_lock()/part_stat_unlock() have this race too. */ +#if BITS_PER_LONG == 32 + unsigned long flags; + local_irq_save(flags); +#else preempt_disable(); +#endif p = &s->stat_percpu[smp_processor_id()][entry]; if (!end) { @@ -478,7 +485,11 @@ static void dm_stat_for_entry(struct dm_stat *s, size_t entry, p->ticks[idx] += duration; } +#if BITS_PER_LONG == 32 + local_irq_restore(flags); +#else preempt_enable(); +#endif } static void __dm_stat_bio(struct dm_stat *s, unsigned long bi_rw, |