From 89a09141df6ac1c3821fbe44ca8384eb37692965 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 16 Mar 2007 13:38:26 -0800 Subject: [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 --- mm/backing-dev.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'mm/backing-dev.c') diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f50a2811f9d..e5de3781d3f 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -55,6 +55,22 @@ long congestion_wait(int rw, long timeout) } EXPORT_SYMBOL(congestion_wait); +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)) + ret = -ERESTARTSYS; + else + ret = io_schedule_timeout(timeout); + finish_wait(wqh, &wait); + return ret; +} +EXPORT_SYMBOL(congestion_wait_interruptible); + /** * congestion_end - wake up sleepers on a congested backing_dev_info * @rw: READ or WRITE -- cgit v1.2.3