From 57fd5a5ff8b48b99e90b22fc143082aba755c6c0 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 7 Aug 2009 09:59:15 -0400 Subject: [PATCH] Btrfs: tweak congestion backoff The btrfs io submission thread tries to back off congested devices in favor of rotating off to another disk. But, it tries to make sure it submits at least some IO before rotating on (the others may be congested too), and so it has a magic number of requests it tries to write before it hops. This makes the magic number smaller. Testing shows that we're spending too much time on congested devices and leaving the other devices idle. Signed-off-by: Chris Mason --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 5dbefd11b4a..a7e53773e74 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -276,7 +276,7 @@ loop_lock: * is now congested. Back off and let other work structs * run instead */ - if (pending && bdi_write_congested(bdi) && batch_run > 32 && + if (pending && bdi_write_congested(bdi) && batch_run > 8 && fs_info->fs_devices->open_devices > 1) { struct io_context *ioc; -- 2.20.1