From: William Lee Irwin III <wli@holomorphy.com>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Hugh Dickins <hugh@veritas.com>,
lkml <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org
Subject: Re: 2.5.48-mm1
Date: Thu, 21 Nov 2002 17:08:53 -0800 [thread overview]
Message-ID: <20021122010853.GI11776@holomorphy.com> (raw)
In-Reply-To: <Pine.LNX.3.96.1021121160056.10456D-100000@gatekeeper.tmr.com>
On Thu, Nov 21, 2002 at 04:04:25PM -0500, Bill Davidsen wrote:
> This is purely a performance decision. If you want to avoid bad latency on
> reads then you have to throttle writes. The loop_thread will make the
> system just as slow as a user application writing the same number of
> pages.
> If you want io scheduling you will deliberately slow writes to let reads
> happen in reasonable time. And vice-versa I imagine, although I don't
> think I've seen that case.
Not entirely so. This is just a scheduling decision that has to
discriminate between blocking and nonblocking requests and prevent
starvation of the blocking requests. Write throttling is an
oversimplification that functions poorly.
Bill
WARNING: multiple messages have this Message-ID (diff)
From: William Lee Irwin III <wli@holomorphy.com>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Hugh Dickins <hugh@veritas.com>,
lkml <linux-kernel@vger.kernel.org>,
linux-mm@kvack.org
Subject: Re: 2.5.48-mm1
Date: Thu, 21 Nov 2002 17:08:53 -0800 [thread overview]
Message-ID: <20021122010853.GI11776@holomorphy.com> (raw)
In-Reply-To: <Pine.LNX.3.96.1021121160056.10456D-100000@gatekeeper.tmr.com>
On Thu, Nov 21, 2002 at 04:04:25PM -0500, Bill Davidsen wrote:
> This is purely a performance decision. If you want to avoid bad latency on
> reads then you have to throttle writes. The loop_thread will make the
> system just as slow as a user application writing the same number of
> pages.
> If you want io scheduling you will deliberately slow writes to let reads
> happen in reasonable time. And vice-versa I imagine, although I don't
> think I've seen that case.
Not entirely so. This is just a scheduling decision that has to
discriminate between blocking and nonblocking requests and prevent
starvation of the blocking requests. Write throttling is an
oversimplification that functions poorly.
Bill
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/
next prev parent reply other threads:[~2002-11-22 1:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-11-19 9:16 2.5.48-mm1 Andrew Morton
2002-11-19 9:16 ` 2.5.48-mm1 Andrew Morton
2002-11-19 10:52 ` 2.5.48-mm1 Nick Piggin
2002-11-19 10:52 ` 2.5.48-mm1 Nick Piggin
2002-11-19 14:05 ` 2.5.48-mm1 Hugh Dickins
2002-11-19 14:05 ` 2.5.48-mm1 Hugh Dickins
2002-11-21 21:04 ` 2.5.48-mm1 Bill Davidsen
2002-11-21 21:04 ` 2.5.48-mm1 Bill Davidsen
2002-11-22 1:08 ` William Lee Irwin III [this message]
2002-11-22 1:08 ` 2.5.48-mm1 William Lee Irwin III
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=20021122010853.GI11776@holomorphy.com \
--to=wli@holomorphy.com \
--cc=davidsen@tmr.com \
--cc=hugh@veritas.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.