[PATCH] md: allow sync-speed to be controlled per-device (88202a0c) · Commits · EulixOS / Software / Kernel

Documentation/md.txt

+22 −0

Original line number	Diff line number	Diff line
		@@ -207,6 +207,28 @@ All md devices contain:
		available. It will then appear at md/dev-XXX (depending on the
		name of the device) and further configuration is then possible.

		sync_speed_min
		sync_speed_max
		This are similar to /proc/sys/dev/raid/speed_limit_{min,max}
		however they only apply to the particular array.
		If no value has been written to these, of if the word 'system'
		is written, then the system-wide value is used. If a value,
		in kibibytes-per-second is written, then it is used.
		When the files are read, they show the currently active value
		followed by "(local)" or "(system)" depending on whether it is
		a locally set or system-wide value.

		sync_completed
		This shows the number of sectors that have been completed of
		whatever the current sync_action is, followed by the number of
		sectors in total that could need to be processed. The two
		numbers are separated by a '/' thus effectively showing one
		value, a fraction of the process that is complete.

		sync_speed
		This shows the current actual speed, in K/sec, of the current
		sync_action. It is averaged over the last 30 seconds.


		As component devices are added to an md array, they appear in the 'md'
		directory as new directories named

drivers/md/md.c

+105 −5

Original line number	Diff line number	Diff line
		@@ -81,10 +81,22 @@ static DEFINE_SPINLOCK(pers_lock);
		* idle IO detection.
		*
		* you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
		* or /sys/block/mdX/md/sync_speed_{min,max}
		*/

		static int sysctl_speed_limit_min = 1000;
		static int sysctl_speed_limit_max = 200000;
		static inline int speed_min(mddev_t *mddev)
		{
		return mddev->sync_speed_min ?
		mddev->sync_speed_min : sysctl_speed_limit_min;
		}

		static inline int speed_max(mddev_t *mddev)
		{
		return mddev->sync_speed_max ?
		mddev->sync_speed_max : sysctl_speed_limit_max;
		}

		static struct ctl_table_header *raid_table_header;

		@@ -2197,6 +2209,90 @@ md_scan_mode = __ATTR(sync_action, S_IRUGO\|S_IWUSR, action_show, action_store);
		static struct md_sysfs_entry
		md_mismatches = __ATTR_RO(mismatch_cnt);

		static ssize_t
		sync_min_show(mddev_t mddev, char page)
		{
		return sprintf(page, "%d (%s)\n", speed_min(mddev),
		mddev->sync_speed_min ? "local": "system");
		}

		static ssize_t
		sync_min_store(mddev_t mddev, const char buf, size_t len)
		{
		int min;
		char *e;
		if (strncmp(buf, "system", 6)==0) {
		mddev->sync_speed_min = 0;
		return len;
		}
		min = simple_strtoul(buf, &e, 10);
		if (buf == e \|\| (e && e != '\n') \|\| min <= 0)
		return -EINVAL;
		mddev->sync_speed_min = min;
		return len;
		}

		static struct md_sysfs_entry md_sync_min =
		__ATTR(sync_speed_min, S_IRUGO\|S_IWUSR, sync_min_show, sync_min_store);

		static ssize_t
		sync_max_show(mddev_t mddev, char page)
		{
		return sprintf(page, "%d (%s)\n", speed_max(mddev),
		mddev->sync_speed_max ? "local": "system");
		}

		static ssize_t
		sync_max_store(mddev_t mddev, const char buf, size_t len)
		{
		int max;
		char *e;
		if (strncmp(buf, "system", 6)==0) {
		mddev->sync_speed_max = 0;
		return len;
		}
		max = simple_strtoul(buf, &e, 10);
		if (buf == e \|\| (e && e != '\n') \|\| max <= 0)
		return -EINVAL;
		mddev->sync_speed_max = max;
		return len;
		}

		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_speed_show(mddev_t mddev, char page)
		{
		unsigned long resync, dt, db;
		resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
		dt = ((jiffies - mddev->resync_mark) / HZ);
		if (!dt) dt++;
		db = resync - (mddev->resync_mark_cnt);
		return sprintf(page, "%ld\n", db/dt/2); /* K/sec */
		}

		static struct md_sysfs_entry
		md_sync_speed = __ATTR_RO(sync_speed);

		static ssize_t
		sync_completed_show(mddev_t mddev, char page)
		{
		unsigned long max_blocks, resync;

		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
		max_blocks = mddev->resync_max_sectors;
		else
		max_blocks = mddev->size << 1;

		resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
		return sprintf(page, "%lu / %lu\n", resync, max_blocks);
		}

		static struct md_sysfs_entry
		md_sync_completed = __ATTR_RO(sync_completed);

		static struct attribute *md_default_attrs[] = {
		&md_level.attr,
		&md_raid_disks.attr,
		@@ -2210,6 +2306,10 @@ static struct attribute *md_default_attrs[] = {
		static struct attribute *md_redundancy_attrs[] = {
		&md_scan_mode.attr,
		&md_mismatches.attr,
		&md_sync_min.attr,
		&md_sync_max.attr,
		&md_sync_speed.attr,
		&md_sync_completed.attr,
		NULL,
		};
		static struct attribute_group md_redundancy_group = {
		@@ -4433,10 +4533,10 @@ static void md_do_sync(mddev_t *mddev)

		printk(KERN_INFO "md: syncing RAID array %s\n", mdname(mddev));
		printk(KERN_INFO "md: minimum _guaranteed_ reconstruction speed:"
		" %d KB/sec/disc.\n", sysctl_speed_limit_min);
		" %d KB/sec/disc.\n", speed_min(mddev));
		printk(KERN_INFO "md: using maximum available idle IO bandwidth "
		"(but not more than %d KB/sec) for reconstruction.\n",
		sysctl_speed_limit_max);
		speed_max(mddev));

		is_mddev_idle(mddev); /* this also initializes IO event counters */
		/* we don't use the checkpoint if there's a bitmap */
		@@ -4477,7 +4577,7 @@ static void md_do_sync(mddev_t *mddev)

		skipped = 0;
		sectors = mddev->pers->sync_request(mddev, j, &skipped,
		currspeed < sysctl_speed_limit_min);
		currspeed < speed_min(mddev));
		if (sectors == 0) {
		set_bit(MD_RECOVERY_ERR, &mddev->recovery);
		goto out;
		@@ -4542,8 +4642,8 @@ static void md_do_sync(mddev_t *mddev)
		currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
		/((jiffies-mddev->resync_mark)/HZ +1) +1;

		if (currspeed > sysctl_speed_limit_min) {
		if ((currspeed > sysctl_speed_limit_max) \|\|
		if (currspeed > speed_min(mddev)) {
		if ((currspeed > speed_max(mddev)) \|\|
		!is_mddev_idle(mddev)) {
		msleep(500);
		goto repeat;

include/linux/raid/md_k.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -143,6 +143,10 @@ struct mddev_s
		sector_t resync_mismatches; /* count of sectors where
		* parity/replica mismatch found
		*/
		/* if zero, use the system-wide default */
		int sync_speed_min;
		int sync_speed_max;

		int ok_start_degraded;
		/* recovery/resync flags
		* NEEDED: we might need to start a resync/recover