@@ -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);
@@ -5145,6 +5168,35 @@ sync_max_store(struct mddev *mddev, const char *buf, size_t 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_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)
{
@@ -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,
@@ -8927,6 +8980,23 @@ 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 +9265,8 @@ 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.
@@ -484,6 +484,7 @@ struct mddev {
/* if zero, use the system-wide default */
int sync_speed_min;
int sync_speed_max;
+ int sync_io_depth;
/* resync even though the same disks are shared among md-devices */
int parallel_resync;