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>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 1ff8418ae0f..db93eee7e54 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1098,6 +1098,8 @@ int __drbd_set_state(struct drbd_conf *mdev,
                 mdev->ov_left = mdev->rs_total
                               - BM_SECT_TO_BIT(mdev->ov_position);
                 mdev->rs_start = now;
+                mdev->rs_last_events = 0;
+                mdev->rs_last_sect_ev = 0;
                 mdev->ov_last_oos_size = 0;
                 mdev->ov_last_oos_start = 0;
 
@@ -2706,7 +2708,8 @@ static void drbd_set_defaults(struct drbd_conf *mdev)
                 /* .c_plan_ahead = */   DRBD_C_PLAN_AHEAD_DEF,
                 /* .c_delay_target = */ DRBD_C_DELAY_TARGET_DEF,
                 /* .c_fill_target = */  DRBD_C_FILL_TARGET_DEF,
-                /* .c_max_rate = */     DRBD_C_MAX_RATE_DEF
+                /* .c_max_rate = */     DRBD_C_MAX_RATE_DEF,
+                /* .c_min_rate = */     DRBD_C_MIN_RATE_DEF
         };
 
         /* Have to use that way, because the layout differs between
@@ -2742,6 +2745,7 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
         atomic_set(&mdev->packet_seq, 0);
         atomic_set(&mdev->pp_in_use, 0);
         atomic_set(&mdev->rs_sect_in, 0);
+        atomic_set(&mdev->rs_sect_ev, 0);
 
         mutex_init(&mdev->md_io_mutex);
         mutex_init(&mdev->data.mutex);
@@ -2819,6 +2823,7 @@ void drbd_mdev_cleanup(struct drbd_conf *mdev)
         mdev->rs_total     =
         mdev->rs_failed    = 0;
         mdev->rs_last_events = 0;
+        mdev->rs_last_sect_ev = 0;
         for (i = 0; i < DRBD_SYNC_MARKS; i++) {
                 mdev->rs_mark_left[i] = 0;
                 mdev->rs_mark_time[i] = 0;