From: Eivind Sarto Date: Tue, 10 Jun 2014 00:06:19 +0000 (-0700) Subject: raid5: speedup sync_request processing X-Git-Tag: omap-for-v3.16/fixes-against-rc1~58^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=053f5b6525ae32da397e6c47721961f800d2c924;p=pandora-kernel.git raid5: speedup sync_request processing The raid5 sync_request() processing calls handle_stripe() within the context of the resync-thread. The resync-thread issues the first set of read requests and this adds execution latency and slows down the scheduling of the next sync_request(). The current rebuild/resync speed of raid5 is not much faster than what rotational HDDs can sustain. Testing the following patch on a 6-drive array, I can increase the rebuild speed from 100 MB/s to 175 MB/s. The sync_request() now just sets STRIPE_HANDLE and releases the stripe. This creates some more parallelism between the resync-thread and raid5 kernel daemon. Signed-off-by: Eivind Sarto Signed-off-by: NeilBrown --- Reading git-diff-tree failed