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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2014-04-22 16:37:16 +0200 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2014-07-10 18:35:06 +0200 |
| commit | 7f34f61490ee87a470cf229069d59b0987f42a59 (patch) | |
| tree | e76e93c15ce7283d656f508b5c1c88189bd8be66 | |
| parent | f88c5d90ccca70841af88ba9456ba4aac6d10da8 (diff) | |
| download | linux-7f34f61490ee87a470cf229069d59b0987f42a59.tar.gz linux-7f34f61490ee87a470cf229069d59b0987f42a59.tar.bz2 linux-7f34f61490ee87a470cf229069d59b0987f42a59.zip | |
drbd: drbd_rs_number_requests: fix unit mismatch in comparison
We try to limit the number of "in-flight" resync requests.
One condition for that is the amount of requested data should not exceed
half of what can be covered by our "max-buffers" setting.
However we compared number of 4k pages with number of in-flight 512 Byte
sectors, and this extra throttle triggered much earlier than intended.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
| -rw-r--r-- | drivers/block/drbd/drbd_worker.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 0b5e4294acf9..9f0acb011f30 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -504,9 +504,9 @@ struct fifo_buffer *fifo_alloc(int fifo_size) static int drbd_rs_controller(struct drbd_device *device, unsigned int sect_in) { struct disk_conf *dc; - unsigned int want; /* The number of sectors we want in the proxy */ + unsigned int want; /* The number of sectors we want in-flight */ int req_sect; /* Number of sectors to request in this turn */ - int correction; /* Number of sectors more we need in the proxy*/ + int correction; /* Number of sectors more we need in-flight */ int cps; /* correction per invocation of drbd_rs_controller() */ int steps; /* Number of time steps to plan ahead */ int curr_corr; @@ -577,8 +577,13 @@ static int drbd_rs_number_requests(struct drbd_device *device) * potentially causing a distributed deadlock on congestion during * online-verify or (checksum-based) resync, if max-buffers, * socket buffer sizes and resync rate settings are mis-configured. */ - if (mxb - device->rs_in_flight < number) - number = mxb - device->rs_in_flight; + + /* note that "number" is in units of "BM_BLOCK_SIZE" (which is 4k), + * mxb (as used here, and in drbd_alloc_pages on the peer) is + * "number of pages" (typically also 4k), + * but "rs_in_flight" is in "sectors" (512 Byte). */ + if (mxb - device->rs_in_flight/8 < number) + number = mxb - device->rs_in_flight/8; return number; } |