From: Christoph Hellwig <hch@infradead.org>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: Alasdair G Kergon <agk@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
axboe@kernel.dk, dm-devel <dm-devel@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: Queue upcall locking (was: [dm-devel] [RFC][PATCH] fix dm_any_congested() to properly sync up with suspend code path)
Date: Tue, 11 Nov 2008 13:22:11 -0500 [thread overview]
Message-ID: <20081111182211.GC25049@infradead.org> (raw)
In-Reply-To: <Pine.LNX.4.64.0811100933520.16965@hs20-bc2-1.build.redhat.com>
On Mon, Nov 10, 2008 at 09:40:18AM -0500, Mikulas Patocka wrote:
> > - If the device is suspended, the response should be that it is
> > congested, I'd have thought.
>
> Yes, but these congestion upcalls are used only for optimization and the
> device is suspended for so small time, that it doesn't matter if we
> optimize io acces in small moment or not.
We use device congested to not block pdflush on a device that can't
currently accept I/O. For a suspended device congested is always
correct, pdflush will just come back a little later and in the mean time
write out stuff that doesn't delay it.
next prev parent reply other threads:[~2008-11-11 18:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1225944008.14830.1101.camel@chandra-ubuntu>
2008-11-10 13:11 ` Mikulas Patocka
2008-11-10 13:54 ` Christoph Hellwig
2008-11-10 14:19 ` Mikulas Patocka
2008-11-10 14:26 ` Peter Zijlstra
2008-11-10 14:32 ` Mikulas Patocka
2008-11-10 14:46 ` Peter Zijlstra
2008-11-10 14:55 ` Mikulas Patocka
2008-11-10 14:35 ` Alasdair G Kergon
2008-11-11 18:18 ` Christoph Hellwig
2008-11-11 22:08 ` Mikulas Patocka
2008-11-10 14:27 ` Alasdair G Kergon
2008-11-10 14:40 ` Mikulas Patocka
2008-11-11 18:22 ` Christoph Hellwig [this message]
2008-11-11 18:21 ` Christoph Hellwig
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=20081111182211.GC25049@infradead.org \
--to=hch@infradead.org \
--cc=agk@redhat.com \
--cc=axboe@kernel.dk \
--cc=dm-devel@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mpatocka@redhat.com \
/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
all inboxes | Powered by JetHome®