From: Paul Clements Date: Sat, 23 Feb 2008 23:23:50 +0000 (-0800) Subject: NBD: make nbd default to deadline I/O scheduler X-Git-Tag: v2.6.25-rc3~41 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=48f15b93b2c9f4ec9b8af08ab78f7a27db7c8378;p=pandora-kernel.git NBD: make nbd default to deadline I/O scheduler NBD doesn't work well with CFQ (or AS) schedulers, so let's default to something else. The two problems I have experienced with nbd and cfq are: 1) nbd hangs with cfq on RHEL 5 (2.6.18) -- this may well have been fixed There's a similar debian bug that has been filed as well: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=447638 There have been posts to nbd-general mailing list about problems with cfq and nbd also. 2) nbd performs about 10% better (the last time I tested) with deadline vs. cfq (the overhead of cfq doesn't provide much advantage to nbd [not being a real disk], and you end up going through the I/O scheduler on the nbd server anyway, so it makes sense that deadline is better with nbd) Signed-off-by: Paul Clements Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed