From cdd67a74603d0453ddffc24c572aed2ddd1795b8 Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Tue, 4 May 2010 16:57:18 +0200 Subject: [PATCH] drbd: Control the actual resync rate based on the queuing delay of data packets In a setup with a high bandwidth and high latency network, eventually involving deep queues in routers, it is beneficial to only fill those queues up to an limited extend with resync data. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_worker.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 44bf6d1..0bbecf4 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -414,6 +414,18 @@ void resync_timer_fn(unsigned long data) drbd_queue_work(&mdev->data.work, &mdev->resync_work); } +static int calc_resync_rate(struct drbd_conf *mdev) +{ + int d = mdev->data_delay / 1000; /* us -> ms */ + int td = mdev->sync_conf.throttle_th * 100; /* 0.1s -> ms */ + int hd = mdev->sync_conf.hold_off_th * 100; /* 0.1s -> ms */ + int cr = mdev->sync_conf.rate; + + return d <= td ? cr : + d >= hd ? 0 : + cr + (cr * (td - d) / (hd - td)); +} + int w_make_resync_request(struct drbd_conf *mdev, struct drbd_work *w, int cancel) { @@ -446,7 +458,8 @@ int w_make_resync_request(struct drbd_conf *mdev, return 1; } - number = SLEEP_TIME * mdev->sync_conf.rate / ((BM_BLOCK_SIZE/1024)*HZ); + mdev->c_sync_rate = calc_resync_rate(mdev); + number = SLEEP_TIME * mdev->c_sync_rate / ((BM_BLOCK_SIZE / 1024) * HZ); pe = atomic_read(&mdev->rs_pending_cnt); mutex_lock(&mdev->data.mutex); -- 2.7.4