Re: [PATCH 0/4] (RESEND) ext3[34] barrier changes

[Chris Mason]

On Sunday 18 May 2008, Andi Kleen wrote:
> Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes:
> > On Fri, 16 May 2008 14:02:46 -0500
> >
> > Eric Sandeen <sandeen@xxxxxxxxxx> wrote:
> >> A collection of patches to make ext3 & 4 use barriers by
> >> default, and to call blkdev_issue_flush on fsync if they
> >> are enabled.
> >
> > Last time this came up lots of workloads slowed down by 30% so I
> > dropped the patches in horror.
>
> Didn't ext4 have some new checksum trick to avoid them?

I didn't think checksumming avoided barriers completely.  Just the barrier 
before the commit block, not the barrier after.

-chris
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