From: Dan Williams <dan.j.williams@intel.com>
Date: Wed, 5 May 2010 03:41:56 +0000 (-0700)
Subject: raid6: fix recovery performance regression
X-Git-Tag: v2.6.34-rc7~23
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5157b4aa5b7de8787b6318e61bcc285031bb9088;p=pandora-kernel.git

raid6: fix recovery performance regression

The raid6 recovery code should immediately drop back to the optimized
synchronous path when a p+q dma resource is not available.  Otherwise we
run the non-optimized/multi-pass async code in sync mode.

Verified with raid6test (NDISKS=255)

Applies to kernels >= 2.6.32.

Cc: <stable@kernel.org>
Acked-by: NeilBrown <neilb@suse.de>
Reported-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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