Re: Mount ext3 with barrier=1 doesn't send real barrier bio?

From: Ric Wheeler
Date: Thu Aug 21 2008 - 06:45:27 EST


Jens Axboe wrote:
On Wed, Aug 20 2008, Eric Sandeen wrote:
Milan Broz wrote:
Hi,

I run some barrier tests over device-mapper (which currently doesn't
support barrier bio at all) and even if I set barrier=1 in ext3 mount,
there is never any bio with barrier flag... (in 2.6.27-rc)

How is the barrier=1 flag supposed to work in ext3 (JBD) now?
Milan, you're right. Ric saw this same strange behavior when doing some
benchmarking with and without barriers; Chris noticed the change in
submit_bh; I was about to write up a similar patch to what you've sent
already. Jens, does Milan's fix look good to you?

Yep looks good, thanks a lot Milan! I'll send in the patch, unless I'm
badly mistaken we need it for 2.6.26-stable as well.


I think we definitely need it there as well, thanks!

Ric

--
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/