Re: [PATCH 1/2] blktrace: treat flush as barrier

From: Namhyung Kim
Date: Tue May 31 2011 - 06:27:31 EST


2011-05-28 (í), 03:44 -0400, Christoph Hellwig:
> On Sat, May 28, 2011 at 11:09:41AM +0900, Namhyung Kim wrote:
> > AFAIK FLUSH always precedes WRITE and then followed by FUA, so how about
>
> Right now most do because that's how the old barriers worked, but it's
> going to change. For $NEXT + 1 I have a patch that for will make
> xfs sends FUA without flushes in a lot of cases, and afaik some device
> mapper code already does now.
>

OK, thanks for the explanation.

Btw, the point was it seems possible that we can use the 'F' for both
FLUSH and FUA if we distinguish them by their (relative) position in the
output. How do you think? Do you still prefer F/U flags?

Thanks.


--
Regards,
Namhyung Kim


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/