The IO Performance on the already available lv is very bad
during the initial sync when we create a mirror lv. This
patch add the rate limit for every mirror target to control
resync speed.
Signed-off-by: Guangliang Zhao <gz...@suse.com>
---
drivers/md/dm-raid1.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 9bfd057..43e428a 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -13,6 +13,7 @@
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
+#include <linux/ratelimit.h>
#include <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/dm-dirty-log.h>
@@ -26,6 +27,11 @@
#define DM_RAID1_HANDLE_ERRORS 0x01
#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
+/* Default resync interval*/
+#define RESYNC_JIFFIES HZ
+/* Default max resync speed in KB/s */
+#define DEFAULT_RESYNC_SPEED (0xFFFFFFF)
+
static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
/*-----------------------------------------------------------------
@@ -69,6 +75,9 @@ struct mirror_set {
int log_failure;
int leg_failure;
atomic_t suspend;
+ /* recovery speed control */
+ struct ratelimit_state ms_rlimit;
+ struct delayed_work resync_waker;
atomic_t default_mirror; /* Default mirror */
@@ -383,12 +392,18 @@ static void do_recovery(struct mirror_set *ms)
/*
* Copy any already quiesced regions.
*/
- while ((reg = dm_rh_recovery_start(ms->rh))) {
+ while (__ratelimit(&ms->ms_rlimit) &&
+ (reg = dm_rh_recovery_start(ms->rh))) {
r = recover(ms, reg);
if (r)
dm_rh_recovery_end(reg, 0);
}
+ /* Broke off the resync process, so wake up kmirrord later on */
+ if (!ms->in_sync)
+ schedule_delayed_work(&ms->resync_waker,
+ ms->ms_rlimit.interval);
+
/*
* Update the in sync flag.
*/
@@ -842,6 +857,14 @@ static void do_mirror(struct work_struct *work)
do_failures(ms, &failures);
}
+static void do_resync_wake(struct work_struct *work)
+{
+ struct mirror_set *ms =
+ container_of(work, struct mirror_set, resync_waker.work);
+
+ wakeup_mirrord(ms);
+}
+
/*-----------------------------------------------------------------
* Target functions
*---------------------------------------------------------------*/
@@ -852,6 +875,7 @@ static struct mirror_set *alloc_context(unsigned int
nr_mirrors,
{
size_t len;
struct mirror_set *ms = NULL;
+ int burst;
len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
@@ -875,6 +899,10 @@ static struct mirror_set *alloc_context(unsigned int
nr_mirrors,
ms->leg_failure = 0;
atomic_set(&ms->suspend, 0);
atomic_set(&ms->default_mirror, DEFAULT_MIRROR);
+ burst = (DEFAULT_RESYNC_SPEED * (RESYNC_JIFFIES / HZ)) << 1;
+ burst = DIV_ROUND_UP(burst, region_size);
+ ratelimit_state_init(&ms->ms_rlimit, RESYNC_JIFFIES, burst);
+ INIT_DELAYED_WORK(&ms->resync_waker, do_resync_wake);
ms->read_record_pool = mempool_create_slab_pool(MIN_READ_RECORDS,
_dm_raid1_read_record_cache);
--
1.7.10.4
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