69 lines
2.2 KiB
Diff
69 lines
2.2 KiB
Diff
From d48d06cd0d6c390820f1cc0e5f6b00c9b7511ea7 Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Tue, 6 Apr 2010 16:51:31 +0200
|
|
Subject: [PATCH 191/278] 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>
|
|
---
|
|
drivers/md/raid5.c | 7 +++++--
|
|
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 26ef63a..17f5c52 100644
|
|
--- a/drivers/md/raid5.c
|
|
+++ b/drivers/md/raid5.c
|
|
@@ -1253,8 +1253,9 @@ 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++;
|
|
@@ -1306,7 +1307,8 @@ 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
|
|
@@ -4549,6 +4551,7 @@ 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 e10c553..010a969 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
|
|
--
|
|
1.7.10
|
|
|