drbd: new configuration parameter c-min-rate
We now track the data rate of locally submitted resync related requests, and can thus detect non-resync activity on the lower level device. If the current sync rate is above c-min-rate, and the lower level device appears to be busy, we throttle the resyncer. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
parent
80a40e439e
commit
0f0601f4ea
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@ -1513,6 +1513,7 @@ extern int w_restart_disk_io(struct drbd_conf *, struct drbd_work *, int);
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extern void resync_timer_fn(unsigned long data);
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extern void resync_timer_fn(unsigned long data);
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/* drbd_receiver.c */
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/* drbd_receiver.c */
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extern int drbd_rs_should_slow_down(struct drbd_conf *mdev);
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extern int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
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extern int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
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const unsigned rw, const int fault_type);
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const unsigned rw, const int fault_type);
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extern int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list);
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extern int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list);
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@ -1098,6 +1098,8 @@ int __drbd_set_state(struct drbd_conf *mdev,
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mdev->ov_left = mdev->rs_total
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mdev->ov_left = mdev->rs_total
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- BM_SECT_TO_BIT(mdev->ov_position);
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- BM_SECT_TO_BIT(mdev->ov_position);
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mdev->rs_start = now;
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mdev->rs_start = now;
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mdev->rs_last_events = 0;
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mdev->rs_last_sect_ev = 0;
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mdev->ov_last_oos_size = 0;
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mdev->ov_last_oos_size = 0;
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mdev->ov_last_oos_start = 0;
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mdev->ov_last_oos_start = 0;
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@ -2706,7 +2708,8 @@ static void drbd_set_defaults(struct drbd_conf *mdev)
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/* .c_plan_ahead = */ DRBD_C_PLAN_AHEAD_DEF,
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/* .c_plan_ahead = */ DRBD_C_PLAN_AHEAD_DEF,
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/* .c_delay_target = */ DRBD_C_DELAY_TARGET_DEF,
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/* .c_delay_target = */ DRBD_C_DELAY_TARGET_DEF,
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/* .c_fill_target = */ DRBD_C_FILL_TARGET_DEF,
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/* .c_fill_target = */ DRBD_C_FILL_TARGET_DEF,
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/* .c_max_rate = */ DRBD_C_MAX_RATE_DEF
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/* .c_max_rate = */ DRBD_C_MAX_RATE_DEF,
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/* .c_min_rate = */ DRBD_C_MIN_RATE_DEF
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};
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};
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/* Have to use that way, because the layout differs between
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/* Have to use that way, because the layout differs between
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@ -2742,6 +2745,7 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
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atomic_set(&mdev->packet_seq, 0);
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atomic_set(&mdev->packet_seq, 0);
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atomic_set(&mdev->pp_in_use, 0);
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atomic_set(&mdev->pp_in_use, 0);
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atomic_set(&mdev->rs_sect_in, 0);
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atomic_set(&mdev->rs_sect_in, 0);
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atomic_set(&mdev->rs_sect_ev, 0);
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mutex_init(&mdev->md_io_mutex);
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mutex_init(&mdev->md_io_mutex);
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mutex_init(&mdev->data.mutex);
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mutex_init(&mdev->data.mutex);
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@ -2819,6 +2823,7 @@ void drbd_mdev_cleanup(struct drbd_conf *mdev)
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mdev->rs_total =
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mdev->rs_total =
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mdev->rs_failed = 0;
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mdev->rs_failed = 0;
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mdev->rs_last_events = 0;
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mdev->rs_last_events = 0;
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mdev->rs_last_sect_ev = 0;
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for (i = 0; i < DRBD_SYNC_MARKS; i++) {
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for (i = 0; i < DRBD_SYNC_MARKS; i++) {
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mdev->rs_mark_left[i] = 0;
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mdev->rs_mark_left[i] = 0;
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mdev->rs_mark_time[i] = 0;
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mdev->rs_mark_time[i] = 0;
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@ -1604,7 +1604,8 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n
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sc.c_plan_ahead = DRBD_C_PLAN_AHEAD_DEF;
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sc.c_plan_ahead = DRBD_C_PLAN_AHEAD_DEF;
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sc.c_delay_target = DRBD_C_DELAY_TARGET_DEF;
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sc.c_delay_target = DRBD_C_DELAY_TARGET_DEF;
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sc.c_fill_target = DRBD_C_FILL_TARGET_DEF;
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sc.c_fill_target = DRBD_C_FILL_TARGET_DEF;
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sc.c_max_rate = DRBD_C_MAX_RATE_DEF;
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sc.c_max_rate = DRBD_C_MAX_RATE_DEF;
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sc.c_min_rate = DRBD_C_MIN_RATE_DEF;
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} else
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} else
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memcpy(&sc, &mdev->sync_conf, sizeof(struct syncer_conf));
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memcpy(&sc, &mdev->sync_conf, sizeof(struct syncer_conf));
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@ -1561,6 +1561,7 @@ static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_si
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list_add(&e->w.list, &mdev->sync_ee);
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list_add(&e->w.list, &mdev->sync_ee);
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spin_unlock_irq(&mdev->req_lock);
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spin_unlock_irq(&mdev->req_lock);
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atomic_add(data_size >> 9, &mdev->rs_sect_ev);
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if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
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if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
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return TRUE;
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return TRUE;
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@ -2017,17 +2018,66 @@ out_interrupted:
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return FALSE;
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return FALSE;
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}
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}
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/* We may throttle resync, if the lower device seems to be busy,
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* and current sync rate is above c_min_rate.
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*
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* To decide whether or not the lower device is busy, we use a scheme similar
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* to MD RAID is_mddev_idle(): if the partition stats reveal "significant"
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* (more than 64 sectors) of activity we cannot account for with our own resync
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* activity, it obviously is "busy".
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*
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* The current sync rate used here uses only the most recent two step marks,
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* to have a short time average so we can react faster.
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*/
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int drbd_rs_should_slow_down(struct drbd_conf *mdev)
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{
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struct gendisk *disk = mdev->ldev->backing_bdev->bd_contains->bd_disk;
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unsigned long db, dt, dbdt;
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int curr_events;
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int throttle = 0;
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/* feature disabled? */
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if (mdev->sync_conf.c_min_rate == 0)
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return 0;
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curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
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(int)part_stat_read(&disk->part0, sectors[1]) -
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atomic_read(&mdev->rs_sect_ev);
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if (!mdev->rs_last_events || curr_events - mdev->rs_last_events > 64) {
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unsigned long rs_left;
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int i;
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mdev->rs_last_events = curr_events;
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/* sync speed average over the last 2*DRBD_SYNC_MARK_STEP,
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* approx. */
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i = (mdev->rs_last_mark + DRBD_SYNC_MARKS-2) % DRBD_SYNC_MARKS;
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rs_left = drbd_bm_total_weight(mdev) - mdev->rs_failed;
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dt = ((long)jiffies - (long)mdev->rs_mark_time[i]) / HZ;
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if (!dt)
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dt++;
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db = mdev->rs_mark_left[i] - rs_left;
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dbdt = Bit2KB(db/dt);
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if (dbdt > mdev->sync_conf.c_min_rate)
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throttle = 1;
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}
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return throttle;
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}
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static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
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static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
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{
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{
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sector_t sector;
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sector_t sector;
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const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
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const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
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struct drbd_epoch_entry *e;
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struct drbd_epoch_entry *e;
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struct digest_info *di = NULL;
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struct digest_info *di = NULL;
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struct p_block_req *p = (struct p_block_req *)h;
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const int brps = sizeof(*p)-sizeof(*h);
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int size, digest_size;
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int size, digest_size;
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unsigned int fault_type;
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unsigned int fault_type;
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struct p_block_req *p =
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(struct p_block_req *)h;
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const int brps = sizeof(*p)-sizeof(*h);
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if (drbd_recv(mdev, h->payload, brps) != brps)
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if (drbd_recv(mdev, h->payload, brps) != brps)
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return FALSE;
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return FALSE;
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@ -2099,8 +2149,9 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
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} else if (h->command == P_OV_REPLY) {
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} else if (h->command == P_OV_REPLY) {
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e->w.cb = w_e_end_ov_reply;
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e->w.cb = w_e_end_ov_reply;
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dec_rs_pending(mdev);
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dec_rs_pending(mdev);
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/* drbd_rs_begin_io done when we sent this request */
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/* drbd_rs_begin_io done when we sent this request,
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goto submit;
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* but accounting still needs to be done. */
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goto submit_for_resync;
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}
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}
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break;
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break;
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@ -2128,9 +2179,36 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
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goto out_free_e;
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goto out_free_e;
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}
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}
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/* Throttle, drbd_rs_begin_io and submit should become asynchronous
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* wrt the receiver, but it is not as straightforward as it may seem.
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* Various places in the resync start and stop logic assume resync
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* requests are processed in order, requeuing this on the worker thread
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* introduces a bunch of new code for synchronization between threads.
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*
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* Unlimited throttling before drbd_rs_begin_io may stall the resync
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* "forever", throttling after drbd_rs_begin_io will lock that extent
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* for application writes for the same time. For now, just throttle
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* here, where the rest of the code expects the receiver to sleep for
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* a while, anyways.
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*/
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/* Throttle before drbd_rs_begin_io, as that locks out application IO;
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* this defers syncer requests for some time, before letting at least
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* on request through. The resync controller on the receiving side
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* will adapt to the incoming rate accordingly.
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*
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* We cannot throttle here if remote is Primary/SyncTarget:
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* we would also throttle its application reads.
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* In that case, throttling is done on the SyncTarget only.
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*/
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if (mdev->state.peer != R_PRIMARY && drbd_rs_should_slow_down(mdev))
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msleep(100);
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if (drbd_rs_begin_io(mdev, e->sector))
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if (drbd_rs_begin_io(mdev, e->sector))
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goto out_free_e;
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goto out_free_e;
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submit_for_resync:
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atomic_add(size >> 9, &mdev->rs_sect_ev);
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submit:
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submit:
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inc_unacked(mdev);
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inc_unacked(mdev);
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spin_lock_irq(&mdev->req_lock);
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spin_lock_irq(&mdev->req_lock);
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@ -215,10 +215,8 @@ void drbd_endio_sec(struct bio *bio, int error)
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*/
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*/
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void drbd_endio_pri(struct bio *bio, int error)
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void drbd_endio_pri(struct bio *bio, int error)
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{
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{
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unsigned long flags;
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struct drbd_request *req = bio->bi_private;
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struct drbd_request *req = bio->bi_private;
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struct drbd_conf *mdev = req->mdev;
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struct drbd_conf *mdev = req->mdev;
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struct bio_and_error m;
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enum drbd_req_event what;
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enum drbd_req_event what;
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int uptodate = bio_flagged(bio, BIO_UPTODATE);
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int uptodate = bio_flagged(bio, BIO_UPTODATE);
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@ -244,12 +242,7 @@ void drbd_endio_pri(struct bio *bio, int error)
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bio_put(req->private_bio);
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bio_put(req->private_bio);
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req->private_bio = ERR_PTR(error);
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req->private_bio = ERR_PTR(error);
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spin_lock_irqsave(&mdev->req_lock, flags);
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req_mod(req, what);
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__req_mod(req, what, &m);
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spin_unlock_irqrestore(&mdev->req_lock, flags);
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if (m.bio)
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complete_master_bio(mdev, &m);
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}
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}
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int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
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int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
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@ -376,6 +369,9 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
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if (!get_ldev(mdev))
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if (!get_ldev(mdev))
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return -EIO;
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return -EIO;
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if (drbd_rs_should_slow_down(mdev))
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goto defer;
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/* GFP_TRY, because if there is no memory available right now, this may
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/* GFP_TRY, because if there is no memory available right now, this may
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* be rescheduled for later. It is "only" background resync, after all. */
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* be rescheduled for later. It is "only" background resync, after all. */
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e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);
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e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);
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@ -387,6 +383,7 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
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list_add(&e->w.list, &mdev->read_ee);
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list_add(&e->w.list, &mdev->read_ee);
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spin_unlock_irq(&mdev->req_lock);
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spin_unlock_irq(&mdev->req_lock);
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atomic_add(size >> 9, &mdev->rs_sect_ev);
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if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0)
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if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0)
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return 0;
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return 0;
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@ -512,8 +509,9 @@ int w_make_resync_request(struct drbd_conf *mdev,
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sector_t sector;
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sector_t sector;
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const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
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const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
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int max_segment_size;
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int max_segment_size;
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int number, i, rollback_i, size, pe, mx;
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int number, rollback_i, size, pe, mx;
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int align, queued, sndbuf;
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int align, queued, sndbuf;
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int i = 0;
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if (unlikely(cancel))
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if (unlikely(cancel))
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return 1;
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return 1;
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@ -549,7 +547,14 @@ int w_make_resync_request(struct drbd_conf *mdev,
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mdev->c_sync_rate = mdev->sync_conf.rate;
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mdev->c_sync_rate = mdev->sync_conf.rate;
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number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ);
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number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ);
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}
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}
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pe = atomic_read(&mdev->rs_pending_cnt);
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/* Throttle resync on lower level disk activity, which may also be
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* caused by application IO on Primary/SyncTarget.
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* Keep this after the call to drbd_rs_controller, as that assumes
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* to be called as precisely as possible every SLEEP_TIME,
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* and would be confused otherwise. */
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if (drbd_rs_should_slow_down(mdev))
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goto requeue;
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mutex_lock(&mdev->data.mutex);
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mutex_lock(&mdev->data.mutex);
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if (mdev->data.socket)
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if (mdev->data.socket)
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@ -563,6 +568,7 @@ int w_make_resync_request(struct drbd_conf *mdev,
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mx = number;
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mx = number;
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/* Limit the number of pending RS requests to no more than the peer's receive buffer */
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/* Limit the number of pending RS requests to no more than the peer's receive buffer */
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pe = atomic_read(&mdev->rs_pending_cnt);
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if ((pe + number) > mx) {
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if ((pe + number) > mx) {
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number = mx - pe;
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number = mx - pe;
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}
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}
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@ -1492,6 +1498,8 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
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mdev->rs_failed = 0;
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mdev->rs_failed = 0;
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mdev->rs_paused = 0;
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mdev->rs_paused = 0;
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mdev->rs_same_csum = 0;
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mdev->rs_same_csum = 0;
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mdev->rs_last_events = 0;
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mdev->rs_last_sect_ev = 0;
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mdev->rs_total = tw;
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mdev->rs_total = tw;
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mdev->rs_start = now;
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mdev->rs_start = now;
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for (i = 0; i < DRBD_SYNC_MARKS; i++) {
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for (i = 0; i < DRBD_SYNC_MARKS; i++) {
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@ -1516,6 +1524,7 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
|
||||||
}
|
}
|
||||||
|
|
||||||
atomic_set(&mdev->rs_sect_in, 0);
|
atomic_set(&mdev->rs_sect_in, 0);
|
||||||
|
atomic_set(&mdev->rs_sect_ev, 0);
|
||||||
mdev->rs_in_flight = 0;
|
mdev->rs_in_flight = 0;
|
||||||
mdev->rs_planed = 0;
|
mdev->rs_planed = 0;
|
||||||
spin_lock(&mdev->peer_seq_lock);
|
spin_lock(&mdev->peer_seq_lock);
|
||||||
|
|
|
@ -150,5 +150,9 @@
|
||||||
#define DRBD_C_MAX_RATE_MAX (4 << 20)
|
#define DRBD_C_MAX_RATE_MAX (4 << 20)
|
||||||
#define DRBD_C_MAX_RATE_DEF 102400
|
#define DRBD_C_MAX_RATE_DEF 102400
|
||||||
|
|
||||||
|
#define DRBD_C_MIN_RATE_MIN 0 /* kByte/sec */
|
||||||
|
#define DRBD_C_MIN_RATE_MAX (4 << 20)
|
||||||
|
#define DRBD_C_MIN_RATE_DEF 4096
|
||||||
|
|
||||||
#undef RANGE
|
#undef RANGE
|
||||||
#endif
|
#endif
|
||||||
|
|
|
@ -92,6 +92,7 @@ NL_PACKET(syncer_conf, 8,
|
||||||
NL_INTEGER( 77, T_MAY_IGNORE, c_delay_target)
|
NL_INTEGER( 77, T_MAY_IGNORE, c_delay_target)
|
||||||
NL_INTEGER( 78, T_MAY_IGNORE, c_fill_target)
|
NL_INTEGER( 78, T_MAY_IGNORE, c_fill_target)
|
||||||
NL_INTEGER( 79, T_MAY_IGNORE, c_max_rate)
|
NL_INTEGER( 79, T_MAY_IGNORE, c_max_rate)
|
||||||
|
NL_INTEGER( 80, T_MAY_IGNORE, c_min_rate)
|
||||||
)
|
)
|
||||||
|
|
||||||
NL_PACKET(invalidate, 9, )
|
NL_PACKET(invalidate, 9, )
|
||||||
|
|
Loading…
Reference in a new issue