drbd: The new, smarter resync speed controller
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index fd2cdd4..facb72c 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -928,6 +928,12 @@
WO_bio_barrier
};
+struct fifo_buffer {
+ int *values;
+ unsigned int head_index;
+ unsigned int size;
+};
+
struct drbd_conf {
/* things that are stored as / read from meta data on disk */
unsigned long flags;
@@ -1068,6 +1074,11 @@
u64 ed_uuid; /* UUID of the exposed data */
struct mutex state_mutex;
char congestion_reason; /* Why we where congested... */
+ atomic_t rs_sect_in; /* counter to measure the incoming resync data rate */
+ int c_sync_rate; /* current resync rate after delay_probe magic */
+ struct fifo_buffer rs_plan_s; /* correction values of resync planer */
+ int rs_in_flight; /* resync sectors in flight (to proxy, in proxy and from proxy) */
+ int rs_planed; /* resync sectors already planed */
};
static inline struct drbd_conf *minor_to_mdev(unsigned int minor)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index bff4f59..ed09a84 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2734,6 +2734,7 @@
atomic_set(&mdev->net_cnt, 0);
atomic_set(&mdev->packet_seq, 0);
atomic_set(&mdev->pp_in_use, 0);
+ atomic_set(&mdev->rs_sect_in, 0);
mutex_init(&mdev->md_io_mutex);
mutex_init(&mdev->data.mutex);
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 7d384fd..295b8d5 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1587,6 +1587,8 @@
struct crypto_hash *csums_tfm = NULL;
struct syncer_conf sc;
cpumask_var_t new_cpu_mask;
+ int *rs_plan_s = NULL;
+ int fifo_size;
if (!zalloc_cpumask_var(&new_cpu_mask, GFP_KERNEL)) {
retcode = ERR_NOMEM;
@@ -1687,6 +1689,16 @@
if (retcode != NO_ERROR)
goto fail;
+ fifo_size = (sc.c_plan_ahead * 10 * SLEEP_TIME) / HZ;
+ if (fifo_size != mdev->rs_plan_s.size && fifo_size > 0) {
+ rs_plan_s = kzalloc(sizeof(int) * fifo_size, GFP_KERNEL);
+ if (!rs_plan_s) {
+ dev_err(DEV, "kmalloc of fifo_buffer failed");
+ retcode = ERR_NOMEM;
+ goto fail;
+ }
+ }
+
/* ok, assign the rest of it as well.
* lock against receive_SyncParam() */
spin_lock(&mdev->peer_seq_lock);
@@ -1703,6 +1715,15 @@
mdev->verify_tfm = verify_tfm;
verify_tfm = NULL;
}
+
+ if (fifo_size != mdev->rs_plan_s.size) {
+ kfree(mdev->rs_plan_s.values);
+ mdev->rs_plan_s.values = rs_plan_s;
+ mdev->rs_plan_s.size = fifo_size;
+ mdev->rs_planed = 0;
+ rs_plan_s = NULL;
+ }
+
spin_unlock(&mdev->peer_seq_lock);
if (get_ldev(mdev)) {
@@ -1734,6 +1755,7 @@
kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
fail:
+ kfree(rs_plan_s);
free_cpumask_var(new_cpu_mask);
crypto_free_hash(csums_tfm);
crypto_free_hash(verify_tfm);
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 34bea97..5f80b22 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1640,6 +1640,8 @@
drbd_send_ack_dp(mdev, P_NEG_ACK, p);
}
+ atomic_add(data_size >> 9, &mdev->rs_sect_in);
+
return ok;
}
@@ -2810,6 +2812,8 @@
struct crypto_hash *verify_tfm = NULL;
struct crypto_hash *csums_tfm = NULL;
const int apv = mdev->agreed_pro_version;
+ int *rs_plan_s = NULL;
+ int fifo_size = 0;
exp_max_sz = apv <= 87 ? sizeof(struct p_rs_param)
: apv == 88 ? sizeof(struct p_rs_param)
@@ -2904,6 +2908,15 @@
mdev->sync_conf.c_delay_target = be32_to_cpu(p->c_delay_target);
mdev->sync_conf.c_fill_target = be32_to_cpu(p->c_fill_target);
mdev->sync_conf.c_max_rate = be32_to_cpu(p->c_max_rate);
+
+ fifo_size = (mdev->sync_conf.c_plan_ahead * 10 * SLEEP_TIME) / HZ;
+ if (fifo_size != mdev->rs_plan_s.size && fifo_size > 0) {
+ rs_plan_s = kzalloc(sizeof(int) * fifo_size, GFP_KERNEL);
+ if (!rs_plan_s) {
+ dev_err(DEV, "kmalloc of fifo_buffer failed");
+ goto disconnect;
+ }
+ }
}
spin_lock(&mdev->peer_seq_lock);
@@ -2922,6 +2935,12 @@
mdev->csums_tfm = csums_tfm;
dev_info(DEV, "using csums-alg: \"%s\"\n", p->csums_alg);
}
+ if (fifo_size != mdev->rs_plan_s.size) {
+ kfree(mdev->rs_plan_s.values);
+ mdev->rs_plan_s.values = rs_plan_s;
+ mdev->rs_plan_s.size = fifo_size;
+ mdev->rs_planed = 0;
+ }
spin_unlock(&mdev->peer_seq_lock);
}
@@ -4202,6 +4221,7 @@
/* rs_same_csums is supposed to count in units of BM_BLOCK_SIZE */
mdev->rs_same_csum += (blksize >> BM_BLOCK_SHIFT);
dec_rs_pending(mdev);
+ atomic_add(blksize >> 9, &mdev->rs_sect_in);
return TRUE;
}
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index d94720f..fd3e1e9 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -422,6 +422,89 @@
drbd_queue_work(&mdev->data.work, &mdev->resync_work);
}
+static void fifo_set(struct fifo_buffer *fb, int value)
+{
+ int i;
+
+ for (i = 0; i < fb->size; i++)
+ fb->values[i] += value;
+}
+
+static int fifo_push(struct fifo_buffer *fb, int value)
+{
+ int ov;
+
+ ov = fb->values[fb->head_index];
+ fb->values[fb->head_index++] = value;
+
+ if (fb->head_index >= fb->size)
+ fb->head_index = 0;
+
+ return ov;
+}
+
+static void fifo_add_val(struct fifo_buffer *fb, int value)
+{
+ int i;
+
+ for (i = 0; i < fb->size; i++)
+ fb->values[i] += value;
+}
+
+int drbd_rs_controller(struct drbd_conf *mdev)
+{
+ unsigned int sect_in; /* Number of sectors that came in since the last turn */
+ unsigned int want; /* The number of sectors we want in the proxy */
+ int req_sect; /* Number of sectors to request in this turn */
+ int correction; /* Number of sectors more we need in the proxy*/
+ int cps; /* correction per invocation of drbd_rs_controller() */
+ int steps; /* Number of time steps to plan ahead */
+ int curr_corr;
+ int max_sect;
+
+ sect_in = atomic_xchg(&mdev->rs_sect_in, 0); /* Number of sectors that came in */
+ mdev->rs_in_flight -= sect_in;
+
+ spin_lock(&mdev->peer_seq_lock); /* get an atomic view on mdev->rs_plan_s */
+
+ steps = mdev->rs_plan_s.size; /* (mdev->sync_conf.c_plan_ahead * 10 * SLEEP_TIME) / HZ; */
+
+ if (mdev->rs_in_flight + sect_in == 0) { /* At start of resync */
+ want = ((mdev->sync_conf.rate * 2 * SLEEP_TIME) / HZ) * steps;
+ } else { /* normal path */
+ want = mdev->sync_conf.c_fill_target ? mdev->sync_conf.c_fill_target :
+ sect_in * mdev->sync_conf.c_delay_target * HZ / (SLEEP_TIME * 10);
+ }
+
+ correction = want - mdev->rs_in_flight - mdev->rs_planed;
+
+ /* Plan ahead */
+ cps = correction / steps;
+ fifo_add_val(&mdev->rs_plan_s, cps);
+ mdev->rs_planed += cps * steps;
+
+ /* What we do in this step */
+ curr_corr = fifo_push(&mdev->rs_plan_s, 0);
+ spin_unlock(&mdev->peer_seq_lock);
+ mdev->rs_planed -= curr_corr;
+
+ req_sect = sect_in + curr_corr;
+ if (req_sect < 0)
+ req_sect = 0;
+
+ max_sect = (mdev->sync_conf.c_max_rate * 2 * SLEEP_TIME) / HZ;
+ if (req_sect > max_sect)
+ req_sect = max_sect;
+
+ /*
+ dev_warn(DEV, "si=%u if=%d wa=%u co=%d st=%d cps=%d pl=%d cc=%d rs=%d\n",
+ sect_in, mdev->rs_in_flight, want, correction,
+ steps, cps, mdev->rs_planed, curr_corr, req_sect);
+ */
+
+ return req_sect;
+}
+
int w_make_resync_request(struct drbd_conf *mdev,
struct drbd_work *w, int cancel)
{
@@ -459,7 +542,13 @@
max_segment_size = mdev->agreed_pro_version < 94 ?
queue_max_segment_size(mdev->rq_queue) : DRBD_MAX_SEGMENT_SIZE;
- number = SLEEP_TIME * mdev->sync_conf.rate / ((BM_BLOCK_SIZE / 1024) * HZ);
+ if (mdev->rs_plan_s.size) { /* mdev->sync_conf.c_plan_ahead */
+ number = drbd_rs_controller(mdev) >> (BM_BLOCK_SHIFT - 9);
+ mdev->c_sync_rate = number * HZ * (BM_BLOCK_SIZE / 1024) / SLEEP_TIME;
+ } else {
+ mdev->c_sync_rate = mdev->sync_conf.rate;
+ number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ);
+ }
pe = atomic_read(&mdev->rs_pending_cnt);
mutex_lock(&mdev->data.mutex);
@@ -593,6 +682,7 @@
}
requeue:
+ mdev->rs_in_flight += (i << (BM_BLOCK_SHIFT - 9));
mod_timer(&mdev->resync_timer, jiffies + SLEEP_TIME);
put_ldev(mdev);
return 1;
@@ -1419,6 +1509,12 @@
drbd_resync_finished(mdev);
}
+ atomic_set(&mdev->rs_sect_in, 0);
+ mdev->rs_in_flight = 0;
+ mdev->rs_planed = 0;
+ spin_lock(&mdev->peer_seq_lock);
+ fifo_set(&mdev->rs_plan_s, 0);
+ spin_unlock(&mdev->peer_seq_lock);
/* ns.conn may already be != mdev->state.conn,
* we may have been paused in between, or become paused until
* the timer triggers.