diff options
Diffstat (limited to 'debian/patches-rt/0231-md-raid5-Make-raid5_percpu-handling-RT-aware.patch')
| -rw-r--r-- | debian/patches-rt/0231-md-raid5-Make-raid5_percpu-handling-RT-aware.patch | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/debian/patches-rt/0231-md-raid5-Make-raid5_percpu-handling-RT-aware.patch b/debian/patches-rt/0231-md-raid5-Make-raid5_percpu-handling-RT-aware.patch new file mode 100644 index 000000000..33a40d5fc --- /dev/null +++ b/debian/patches-rt/0231-md-raid5-Make-raid5_percpu-handling-RT-aware.patch @@ -0,0 +1,69 @@ +From 4af1829664e98b9b3ec542a03ee30aeee8f47f6c Mon Sep 17 00:00:00 2001 +From: Thomas Gleixner <tglx@linutronix.de> +Date: Tue, 6 Apr 2010 16:51:31 +0200 +Subject: [PATCH 231/323] md: raid5: Make raid5_percpu handling RT aware +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +__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 9f114b9d8dc6..7e0eb8defeaf 100644 +--- a/drivers/md/raid5.c ++++ b/drivers/md/raid5.c +@@ -2218,8 +2218,9 @@ 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++; +@@ -2278,7 +2279,8 @@ 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(); + } + + static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh) +@@ -7108,6 +7110,7 @@ static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node) + __func__, cpu); + return -ENOMEM; + } ++ spin_lock_init(&per_cpu_ptr(conf->percpu, cpu)->lock); + return 0; + } + +diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h +index 5c05acf20e1f..665fe138ab4f 100644 +--- a/drivers/md/raid5.h ++++ b/drivers/md/raid5.h +@@ -635,6 +635,7 @@ 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 +-- +2.43.0 + |