path: root/mm/backing-dev.c
diff options
authorPeter Zijlstra <>2007-03-16 13:38:26 -0800
committerLinus Torvalds <>2007-03-16 19:25:05 -0700
commit89a09141df6ac1c3821fbe44ca8384eb37692965 (patch)
treeccb21055fca86ac2657b3262ac37eb3e5c44bea0 /mm/backing-dev.c
parentb74a2f0913694556a027795d2954d30523fac4c5 (diff)
[PATCH] nfs: fix congestion control
The current NFS client congestion logic is severly broken, it marks the backing device congested during each nfs_writepages() call but doesn't mirror this in nfs_writepage() which makes for deadlocks. Also it implements its own waitqueue. Replace this by a more regular congestion implementation that puts a cap on the number of active writeback pages and uses the bdi congestion waitqueue. Also always use an interruptible wait since it makes sense to be able to SIGKILL the process even for mounts without 'intr'. Signed-off-by: Peter Zijlstra <> Acked-by: Trond Myklebust <> Cc: Christoph Lameter <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm/backing-dev.c')
1 files changed, 16 insertions, 0 deletions
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f50a2811f9dc..e5de3781d3fe 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -55,6 +55,22 @@ long congestion_wait(int rw, long timeout)
+long congestion_wait_interruptible(int rw, long timeout)
+ long ret;
+ DEFINE_WAIT(wait);
+ wait_queue_head_t *wqh = &congestion_wqh[rw];
+ prepare_to_wait(wqh, &wait, TASK_INTERRUPTIBLE);
+ if (signal_pending(current))
+ else
+ ret = io_schedule_timeout(timeout);
+ finish_wait(wqh, &wait);
+ return ret;
* congestion_end - wake up sleepers on a congested backing_dev_info
* @rw: READ or WRITE