Re: [patch v2 2/6] blk: dont allow discard request merge temporarily
From: Christoph Hellwig <hch@infradead.org>
Date: 2012-03-22 06:28:58
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- 2012-03-21 · Re: [patch v2 2/6] blk: dont allow discard request merge temporarily · Shaohua Li <shli@kernel.org>
- 2012-03-20 · Re: [patch v2 2/6] blk: dont allow discard request merge temporarily · Vivek Goyal <vgoyal@redhat.com>
- 2012-03-16 · [patch v2 2/6] blk: dont allow discard request merge temporarily · Shaohua Li <hidden>
On Wed, Mar 21, 2012 at 10:18:54PM -0400, Martin K. Petersen wrote:
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"Shaohua" == Shaohua Li [off-list ref] writes:Shaohua> Enabling discard merge is required for device with slow discard Shaohua> (and very helpful for raid), Before RAID support there really wasn't much point. That's one of the reasons the current discard merge code has survived despite being completely broken.
I've actually send repeated bug reports about it beeing broken when I enabled async discard in XFS which led to merges, and debugged it down to beeing a problem with merges. But Jens didn't like my patch to mark them nomerged, so we still couldn't commit the async discard support for XFS which would have helped quite a bit with discard performance.