cfq-iosched: a regression

From: Shaohua Li
Date: Mon Aug 15 2011 - 22:46:24 EST

We have a kernel build regression since 3.1-rc1, which is about 10%
regression. The kernel source is in an ext3 filesystem.
Alex Shi bisect it to commit:
commit a07405b7802691d29ab3b23bdc76ee6d006aad0b
Author: Justin TerAvest <teravest@xxxxxxxxxx>
Date: Sun Jul 10 22:09:19 2011 +0200

cfq: Remove special treatment for metadata rqs.

Apparently this is caused by lack metadata preemption, where ext3/ext4
do use READ_META. I didn't see a way to fix the issue, so suggest
reverting the patch.

Reported-by: Alex Shi<alex.shi@xxxxxxxxx>
Reported-by: Shaohua Li<>

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