Re: [PATCH 05/11] direct-io: only inc/dec inode->i_dio_count forfile systems

From: Christoph Hellwig
Date: Thu Oct 24 2013 - 05:47:17 EST

On Thu, Oct 24, 2013 at 10:46:00AM +0100, Jens Axboe wrote:
> On Thu, Oct 24 2013, Jens Axboe wrote:
> > We don't need truncate protection for block devices, so add a flag
> > bypassing this cache line dirtying twice for every IO. This easily
> > contributes to 5-10% of the CPU time on high IOPS O_DIRECT testing.
> There's a merge error in this patch, please find the correct one below.

Btw, I think this patch should not go in with this series but rather via
the VFS tree as it's not related to the blk-mq infrastructure at all.

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