From 90b08710e41a07d4ff0fb8940dcce3a552991a56 Mon Sep 17 00:00:00 2001 From: Bernd Schubert Date: Fri, 23 May 2008 13:04:38 -0700 Subject: md: allow parallel resync of md-devices. In some configurations, a raid6 resync can be limited by CPU speed (Calculating P and Q and moving data) rather than by device speed. In these cases there is nothing to be gained byt serialising resync of arrays that share a device, and doing the resync in parallel can provide benefit. So add a sysfs tunable to flag an array as being allowed to resync in parallel with other arrays that use (a different part of) the same device. Signed-off-by: Bernd Schubert Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/md.c | 40 ++++++++++++++++++++++++++++++++++++---- include/linux/raid/md_k.h | 3 +++ 2 files changed, 39 insertions(+), 4 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index e57213dacd25..295be1a68806 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -74,6 +74,8 @@ static DEFINE_SPINLOCK(pers_lock); static void md_print_devices(void); +static DECLARE_WAIT_QUEUE_HEAD(resync_wait); + #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); } /* @@ -3012,6 +3014,36 @@ degraded_show(mddev_t *mddev, char *page) } static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded); +static ssize_t +sync_force_parallel_show(mddev_t *mddev, char *page) +{ + return sprintf(page, "%d\n", mddev->parallel_resync); +} + +static ssize_t +sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len) +{ + long n; + + if (strict_strtol(buf, 10, &n)) + return -EINVAL; + + if (n != 0 && n != 1) + return -EINVAL; + + mddev->parallel_resync = n; + + if (mddev->sync_thread) + wake_up(&resync_wait); + + return len; +} + +/* force parallel resync, even with shared block devices */ +static struct md_sysfs_entry md_sync_force_parallel = +__ATTR(sync_force_parallel, S_IRUGO|S_IWUSR, + sync_force_parallel_show, sync_force_parallel_store); + static ssize_t sync_speed_show(mddev_t *mddev, char *page) { @@ -3187,6 +3219,7 @@ static struct attribute *md_redundancy_attrs[] = { &md_sync_min.attr, &md_sync_max.attr, &md_sync_speed.attr, + &md_sync_force_parallel.attr, &md_sync_completed.attr, &md_max_sync.attr, &md_suspend_lo.attr, @@ -5487,8 +5520,6 @@ void md_allow_write(mddev_t *mddev) } EXPORT_SYMBOL_GPL(md_allow_write); -static DECLARE_WAIT_QUEUE_HEAD(resync_wait); - #define SYNC_MARKS 10 #define SYNC_MARK_STEP (3*HZ) void md_do_sync(mddev_t *mddev) @@ -5552,8 +5583,9 @@ void md_do_sync(mddev_t *mddev) for_each_mddev(mddev2, tmp) { if (mddev2 == mddev) continue; - if (mddev2->curr_resync && - match_mddev_units(mddev,mddev2)) { + if (!mddev->parallel_resync + && mddev2->curr_resync + && match_mddev_units(mddev, mddev2)) { DEFINE_WAIT(wq); if (mddev < mddev2 && mddev->curr_resync == 2) { /* arbitrarily yield */ diff --git a/include/linux/raid/md_k.h b/include/linux/raid/md_k.h index 812ffa590cff..a6d7ab688ede 100644 --- a/include/linux/raid/md_k.h +++ b/include/linux/raid/md_k.h @@ -180,6 +180,9 @@ struct mddev_s int sync_speed_min; int sync_speed_max; + /* resync even though the same disks are shared among md-devices */ + int parallel_resync; + int ok_start_degraded; /* recovery/resync flags * NEEDED: we might need to start a resync/recover -- cgit v1.2.3-59-g8ed1b