From: Daniel Phillips <phillips@phunq.net>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC] [PATCH] A clean aEvgeniy pproach to writeout throttling
Date: Tue, 11 Dec 2007 12:07:43 -0800 [thread overview]
Message-ID: <200712111207.43156.phillips@phunq.net> (raw)
In-Reply-To: <20071211131514.GB25437@kernel.dk>
On Tuesday 11 December 2007 05:15, Jens Axboe wrote:
> As to the patch in question "fixing" it in the block layer, it's a
> fairly simple work around and I'm not totally against it. If you get
> rid of the ->bi_throttle stuff and just do sanity checks on the
> count, then we could look at getting some testing done.
Oh, sorry I missed that olive branch on first read. Getting rid of
those 8 bytes that bother you requires an extensive rethink of bio
handling in order to make some fields that are not now constant,
constant or at least restored on change. Which would be a good thing
in itself. There are lots of good improvements that can be made to
this subsystem along those lines.
But that is properly a separate project. Quite some time will be needed
to get it right, and should I mention it, everybody needs to be on the
same page or the work will never start. It is therefore a theoretical
solution. We have a practical, tested solution, here and now, and it
is short enough to be understood, unlike any of the previous attempts.
Your argument seems to be that adding 8 bytes to struct bio turns this
beautiful swan into an ugly duck. Actually, because the throttling
reduces the number of bios in flight in a busy system, total memory use
is reduced. When the system is not busy, there are few bios hanging
around so that is not a problem either. Nice, hmm?
Daniel
next prev parent reply other threads:[~2007-12-11 20:07 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-06 0:03 [RFC] [PATCH] A clean approach to writeout throttling Daniel Phillips
2007-12-06 1:24 ` Andrew Morton
2007-12-06 6:21 ` Daniel Phillips
2007-12-06 7:31 ` Andrew Morton
2007-12-06 9:48 ` Daniel Phillips
2007-12-06 11:55 ` Andrew Morton
2007-12-06 15:52 ` Rik van Riel
2007-12-06 17:34 ` Andrew Morton
2007-12-06 17:48 ` Rik van Riel
2007-12-06 20:04 ` Daniel Phillips
2007-12-06 20:27 ` Andrew Morton
2007-12-06 21:27 ` Daniel Phillips
2007-12-06 21:53 ` Bill Davidsen
2007-12-07 0:04 ` Daniel Phillips
2007-12-07 0:29 ` Andrew Morton
2007-12-07 7:13 ` Daniel Phillips
2007-12-10 9:20 ` Daniel Phillips
2007-12-10 10:47 ` Jens Axboe
2007-12-10 11:23 ` [RFC] [PATCH] A clean aEvgeniy pproach " Daniel Phillips
2007-12-10 11:41 ` Jens Axboe
2007-12-10 12:13 ` Daniel Phillips
2007-12-10 12:16 ` Jens Axboe
2007-12-10 12:27 ` Daniel Phillips
2007-12-10 12:32 ` Jens Axboe
2007-12-10 13:04 ` Daniel Phillips
2007-12-10 13:19 ` Jens Axboe
2007-12-10 13:26 ` Daniel Phillips
2007-12-10 13:30 ` Jens Axboe
2007-12-10 13:43 ` Daniel Phillips
2007-12-10 13:53 ` Jens Axboe
2007-12-10 14:17 ` Daniel Phillips
2007-12-11 13:15 ` Jens Axboe
2007-12-11 19:38 ` Daniel Phillips
2007-12-11 20:01 ` Jens Axboe
2007-12-11 20:11 ` Daniel Phillips
2007-12-11 20:07 ` Daniel Phillips [this message]
2007-12-10 11:33 ` [RFC] [PATCH] A clean approach " Daniel Phillips
2007-12-10 21:31 ` Jonathan Corbet
2007-12-10 22:06 ` Pekka Enberg
2007-12-11 4:21 ` Daniel Phillips
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=200712111207.43156.phillips@phunq.net \
--to=phillips@phunq.net \
--cc=akpm@linux-foundation.org \
--cc=jens.axboe@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).