From: Peter Zijlstra <peterz@infradead.org>
To: Martin Knoblauch <spamtrap@knobisoft.de>
Cc: linux-kernel@vger.kernel.org, Fengguang Wu <wfg@mail.ustc.edu.cn>
Subject: Re: Likley stupid question on "throttle_vm_writeout"
Date: Mon, 09 Nov 2009 16:26:33 +0100 [thread overview]
Message-ID: <1257780393.4108.343.camel@laptop> (raw)
In-Reply-To: <799070.68490.qm@web32608.mail.mud.yahoo.com>
On Mon, 2009-11-09 at 07:15 -0800, Martin Knoblauch wrote:
> Hi, (please CC me on replies)
>
> I have a likely stupid question on the function "throttle_vm_writeout". Looking at the code I find:
>
> if (global_page_state(NR_UNSTABLE_NFS) +
> global_page_state(NR_WRITEBACK) <= dirty_thresh)
> break;
> congestion_wait(WRITE, HZ/10);
>
> Shouldn't the NR_FILE_DIRTY pages be considered as well?
Ha, you just trod onto a piece of ugly I'd totally forgotten about ;-)
The intent of throttle_vm_writeout() is to limit the total pages in
writeout and to wait for them to go-away.
Everybody hates the function, nobody managed to actually come up with
anything better.
next prev parent reply other threads:[~2009-11-09 15:26 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-09 15:15 Likley stupid question on "throttle_vm_writeout" Martin Knoblauch
2009-11-09 15:26 ` Peter Zijlstra [this message]
2009-11-10 2:08 ` Wu Fengguang
2009-11-10 6:55 ` KOSAKI Motohiro
2009-11-10 12:01 ` Martin Knoblauch
2009-11-10 13:08 ` Wu Fengguang
2009-11-10 16:11 ` Martin Knoblauch
2009-11-11 0:45 ` Wu Fengguang
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