diff options
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 190 |
1 files changed, 133 insertions, 57 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 9daa78c5fe33..0fde115e921f 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -111,32 +111,48 @@ static void md_wakeup_thread_directly(struct md_thread __rcu *thread); /* Default safemode delay: 200 msec */ #define DEFAULT_SAFEMODE_DELAY ((200 * HZ)/1000 +1) /* - * Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit' - * is 1000 KB/sec, so the extra system load does not show up that much. - * Increase it if you want to have more _guaranteed_ speed. Note that - * the RAID driver will use the maximum available bandwidth if the IO - * subsystem is idle. There is also an 'absolute maximum' reconstruction - * speed limit - in case reconstruction slows down your system despite - * idle IO detection. + * Current RAID-1,4,5,6,10 parallel reconstruction 'guaranteed speed limit' + * is sysctl_speed_limit_min, 1000 KB/sec by default, so the extra system load + * does not show up that much. Increase it if you want to have more guaranteed + * speed. Note that the RAID driver will use the maximum bandwidth + * sysctl_speed_limit_max, 200 MB/sec by default, if the IO subsystem is idle. * - * you can change it via /proc/sys/dev/raid/speed_limit_min and _max. - * or /sys/block/mdX/md/sync_speed_{min,max} + * Background sync IO speed control: + * + * - below speed min: + * no limit; + * - above speed min and below speed max: + * a) if mddev is idle, then no limit; + * b) if mddev is busy handling normal IO, then limit inflight sync IO + * to sync_io_depth; + * - above speed max: + * sync IO can't be issued; + * + * Following configurations can be changed via /proc/sys/dev/raid/ for system + * or /sys/block/mdX/md/ for one array. */ - static int sysctl_speed_limit_min = 1000; static int sysctl_speed_limit_max = 200000; -static inline int speed_min(struct mddev *mddev) +static int sysctl_sync_io_depth = 32; + +static int speed_min(struct mddev *mddev) { return mddev->sync_speed_min ? mddev->sync_speed_min : sysctl_speed_limit_min; } -static inline int speed_max(struct mddev *mddev) +static int speed_max(struct mddev *mddev) { return mddev->sync_speed_max ? mddev->sync_speed_max : sysctl_speed_limit_max; } +static int sync_io_depth(struct mddev *mddev) +{ + return mddev->sync_io_depth ? + mddev->sync_io_depth : sysctl_sync_io_depth; +} + static void rdev_uninit_serial(struct md_rdev *rdev) { if (!test_and_clear_bit(CollisionCheck, &rdev->flags)) @@ -293,14 +309,21 @@ static const struct ctl_table raid_table[] = { .procname = "speed_limit_min", .data = &sysctl_speed_limit_min, .maxlen = sizeof(int), - .mode = S_IRUGO|S_IWUSR, + .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "speed_limit_max", .data = &sysctl_speed_limit_max, .maxlen = sizeof(int), - .mode = S_IRUGO|S_IWUSR, + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "sync_io_depth", + .data = &sysctl_sync_io_depth, + .maxlen = sizeof(int), + .mode = 0644, .proc_handler = proc_dointvec, }, }; @@ -5091,7 +5114,7 @@ static ssize_t sync_min_show(struct mddev *mddev, char *page) { return sprintf(page, "%d (%s)\n", speed_min(mddev), - mddev->sync_speed_min ? "local": "system"); + mddev->sync_speed_min ? "local" : "system"); } static ssize_t @@ -5100,7 +5123,7 @@ sync_min_store(struct mddev *mddev, const char *buf, size_t len) unsigned int min; int rv; - if (strncmp(buf, "system", 6)==0) { + if (strncmp(buf, "system", 6) == 0) { min = 0; } else { rv = kstrtouint(buf, 10, &min); @@ -5120,7 +5143,7 @@ static ssize_t sync_max_show(struct mddev *mddev, char *page) { return sprintf(page, "%d (%s)\n", speed_max(mddev), - mddev->sync_speed_max ? "local": "system"); + mddev->sync_speed_max ? "local" : "system"); } static ssize_t @@ -5129,7 +5152,7 @@ sync_max_store(struct mddev *mddev, const char *buf, size_t len) unsigned int max; int rv; - if (strncmp(buf, "system", 6)==0) { + if (strncmp(buf, "system", 6) == 0) { max = 0; } else { rv = kstrtouint(buf, 10, &max); @@ -5146,6 +5169,35 @@ static struct md_sysfs_entry md_sync_max = __ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store); static ssize_t +sync_io_depth_show(struct mddev *mddev, char *page) +{ + return sprintf(page, "%d (%s)\n", sync_io_depth(mddev), + mddev->sync_io_depth ? "local" : "system"); +} + +static ssize_t +sync_io_depth_store(struct mddev *mddev, const char *buf, size_t len) +{ + unsigned int max; + int rv; + + if (strncmp(buf, "system", 6) == 0) { + max = 0; + } else { + rv = kstrtouint(buf, 10, &max); + if (rv < 0) + return rv; + if (max == 0) + return -EINVAL; + } + mddev->sync_io_depth = max; + return len; +} + +static struct md_sysfs_entry md_sync_io_depth = +__ATTR_RW(sync_io_depth); + +static ssize_t degraded_show(struct mddev *mddev, char *page) { return sprintf(page, "%d\n", mddev->degraded); @@ -5671,6 +5723,7 @@ static struct attribute *md_redundancy_attrs[] = { &md_mismatches.attr, &md_sync_min.attr, &md_sync_max.attr, + &md_sync_io_depth.attr, &md_sync_speed.attr, &md_sync_force_parallel.attr, &md_sync_completed.attr, @@ -8572,50 +8625,55 @@ void md_cluster_stop(struct mddev *mddev) put_cluster_ops(mddev); } -static int is_mddev_idle(struct mddev *mddev, int init) +static bool is_rdev_holder_idle(struct md_rdev *rdev, bool init) { + unsigned long last_events = rdev->last_events; + + if (!bdev_is_partition(rdev->bdev)) + return true; + + /* + * If rdev is partition, and user doesn't issue IO to the array, the + * array is still not idle if user issues IO to other partitions. + */ + rdev->last_events = part_stat_read_accum(rdev->bdev->bd_disk->part0, + sectors) - + part_stat_read_accum(rdev->bdev, sectors); + + return init || rdev->last_events <= last_events; +} + +/* + * mddev is idle if following conditions are matched since last check: + * 1) mddev doesn't have normal IO completed; + * 2) mddev doesn't have inflight normal IO; + * 3) if any member disk is partition, and other partitions don't have IO + * completed; + * + * Noted this checking rely on IO accounting is enabled. + */ +static bool is_mddev_idle(struct mddev *mddev, int init) +{ + unsigned long last_events = mddev->normal_io_events; + struct gendisk *disk; struct md_rdev *rdev; - int idle; - int curr_events; + bool idle = true; - idle = 1; - rcu_read_lock(); - rdev_for_each_rcu(rdev, mddev) { - struct gendisk *disk = rdev->bdev->bd_disk; + disk = mddev_is_dm(mddev) ? mddev->dm_gendisk : mddev->gendisk; + if (!disk) + return true; - if (!init && !blk_queue_io_stat(disk->queue)) - continue; + mddev->normal_io_events = part_stat_read_accum(disk->part0, sectors); + if (!init && (mddev->normal_io_events > last_events || + bdev_count_inflight(disk->part0))) + idle = false; - curr_events = (int)part_stat_read_accum(disk->part0, sectors) - - atomic_read(&disk->sync_io); - /* sync IO will cause sync_io to increase before the disk_stats - * as sync_io is counted when a request starts, and - * disk_stats is counted when it completes. - * So resync activity will cause curr_events to be smaller than - * when there was no such activity. - * non-sync IO will cause disk_stat to increase without - * increasing sync_io so curr_events will (eventually) - * be larger than it was before. Once it becomes - * substantially larger, the test below will cause - * the array to appear non-idle, and resync will slow - * down. - * If there is a lot of outstanding resync activity when - * we set last_event to curr_events, then all that activity - * completing might cause the array to appear non-idle - * and resync will be slowed down even though there might - * not have been non-resync activity. This will only - * happen once though. 'last_events' will soon reflect - * the state where there is little or no outstanding - * resync requests, and further resync activity will - * always make curr_events less than last_events. - * - */ - if (init || curr_events - rdev->last_events > 64) { - rdev->last_events = curr_events; - idle = 0; - } - } + rcu_read_lock(); + rdev_for_each_rcu(rdev, mddev) + if (!is_rdev_holder_idle(rdev, init)) + idle = false; rcu_read_unlock(); + return idle; } @@ -8927,6 +8985,23 @@ static sector_t md_sync_position(struct mddev *mddev, enum sync_action action) } } +static bool sync_io_within_limit(struct mddev *mddev) +{ + int io_sectors; + + /* + * For raid456, sync IO is stripe(4k) per IO, for other levels, it's + * RESYNC_PAGES(64k) per IO. + */ + if (mddev->level == 4 || mddev->level == 5 || mddev->level == 6) + io_sectors = 8; + else + io_sectors = 128; + + return atomic_read(&mddev->recovery_active) < + io_sectors * sync_io_depth(mddev); +} + #define SYNC_MARKS 10 #define SYNC_MARK_STEP (3*HZ) #define UPDATE_FREQUENCY (5*60*HZ) @@ -9195,7 +9270,8 @@ void md_do_sync(struct md_thread *thread) msleep(500); goto repeat; } - if (!is_mddev_idle(mddev, 0)) { + if (!sync_io_within_limit(mddev) && + !is_mddev_idle(mddev, 0)) { /* * Give other IO more of a chance. * The faster the devices, the less we wait. |