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Re: [Qemu-stable] [PATCH for-2.9] thread-pool: add missing qemu_bh_cance
From: |
Kevin Wolf |
Subject: |
Re: [Qemu-stable] [PATCH for-2.9] thread-pool: add missing qemu_bh_cancel in completion function |
Date: |
Fri, 17 Mar 2017 12:55:02 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
Am 16.03.2017 um 17:02 hat Peter Lieven geschrieben:
> commit 3c80ca15 fixed a deadlock scenarion with nested aio_poll invocations.
>
> However, the rescheduling of the completion BH introcuded unnecessary spinning
> in the main-loop. On very fast file backends this can even lead to the
> "WARNING: I/O thread spun for 1000 iterations" message popping up.
>
> Callgrind reports about 3-4% less instructions with this patch running
> qemu-img bench on a ramdisk based VMDK file.
>
> Fixes: 3c80ca158c96ff902a30883a8933e755988948b1
> Cc: address@hidden
> Signed-off-by: Peter Lieven <address@hidden>
Thanks, applied to the block branch.
Kevin