linux-kernel - Re: [RFC] [PATCH] A clean aEvgeniy pproach to writeout throttling

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20071210123244.GG5008@kernel.dk>
Date:	Mon, 10 Dec 2007 13:32:44 +0100
From:	Jens Axboe <jens.axboe@...cle.com>
To:	Daniel Phillips <phillips@...nq.net>
Cc:	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [RFC] [PATCH] A clean aEvgeniy pproach to writeout throttling

On Mon, Dec 10 2007, Daniel Phillips wrote:
> On Monday 10 December 2007 04:16, Jens Axboe wrote:
> > OK, let me get the neon out then. This has nothing to do with
> > throttling, I thought I made it clear that I get why you store the
> > origin queue in ->bi_queue. I'm concerned with the workings of
> > redirecting a bio. Previously we looked up the queue associated with
> > bio->bi_bdev inside the loop in __generic_make_request(), as is
> > REQUIRED to correctly locate a DIFFERENT queue if bio->bi_bdev has
> > been changed to point somewhere else.
> 
> Rhetoric aside, again.
> 
> We are only interested in throttling against the bio->bi_bdev that was 
> stored in the bio at the time of the call to generic_make_request, why 
> should we care about the redirected value?

Let me repeat - this has nothing to do with throttling! You are breaking
the bio redirection by killing that bdev_get_queue() in the
__generic_make_request().

I honestly don't know how to make this any clearer than I already did
above. Sleep on it.

-- 
Jens Axboe

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