diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2010-04-06 16:51:31 +0200 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2011-12-28 16:25:43 -0600 |
| commit | 133993c72b8b765134b4fb81aa7036a6b7f223c0 (patch) | |
| tree | 22d238609c502107d00a54cb7984200e62108336 | |
| parent | a55fe21283d39b3ae46e4a904c7ff5d094a6d86f (diff) | |
md: raid5: Make raid5_percpu handling RT aware
__raid_run_ops() disables preemption with get_cpu() around the access
to the raid5_percpu variables. That causes scheduling while atomic
spews on RT.
Serialize the access to the percpu data with a lock and keep the code
preemptible.
Reported-by: Udo van den Heuvel <udovdh@xs4all.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Udo van den Heuvel <udovdh@xs4all.nl>
| -rw-r--r-- | drivers/md/raid5.c | 7 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 1 |
2 files changed, 6 insertions, 2 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 31670f8d6b65..2b0b96c192c9 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1245,8 +1245,9 @@ static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) struct raid5_percpu *percpu; unsigned long cpu; - cpu = get_cpu(); + cpu = get_cpu_light(); percpu = per_cpu_ptr(conf->percpu, cpu); + spin_lock(&percpu->lock); if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) { ops_run_biofill(sh); overlap_clear++; @@ -1298,7 +1299,8 @@ static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request) if (test_and_clear_bit(R5_Overlap, &dev->flags)) wake_up(&sh->raid_conf->wait_for_overlap); } - put_cpu(); + spin_unlock(&percpu->lock); + put_cpu_light(); } #ifdef CONFIG_MULTICORE_RAID456 @@ -4533,6 +4535,7 @@ static int raid5_alloc_percpu(struct r5conf *conf) break; } per_cpu_ptr(conf->percpu, cpu)->scribble = scribble; + spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock); } #ifdef CONFIG_HOTPLUG_CPU conf->cpu_notify.notifier_call = raid456_cpu_notify; diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index e10c5531f9c5..010a96916bc2 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -405,6 +405,7 @@ struct r5conf { int recovery_disabled; /* per cpu variables */ struct raid5_percpu { + spinlock_t lock; /* Protection for -RT */ struct page *spare_page; /* Used when checking P/Q in raid6 */ void *scribble; /* space for constructing buffer * lists and performing address |