public inbox for linux-arch@vger.kernel.org
 help / color / mirror / Atom feed
From: "David S. Miller" <davem@redhat.com>
To: William Lee Irwin III <wli@holomorphy.com>
Cc: torvalds@osdl.org, linux-arch@vger.kernel.org
Subject: Re: clear_user_highpage()
Date: Wed, 11 Aug 2004 18:01:22 -0700	[thread overview]
Message-ID: <20040811180122.428a9e61.davem@redhat.com> (raw)
In-Reply-To: <20040812004654.GX11200@holomorphy.com>

On Wed, 11 Aug 2004 17:46:54 -0700
William Lee Irwin III <wli@holomorphy.com> wrote:

> The scheduling latency aspect is due to the fact that many cpus have
> caching semantics that require extremely slow uncached accesss to
> prevent cache pollution, and that page zeroing is slow enough of an
> operation to noticeably stall rescheduling userspace.

This wouldn't be an issue on sparc64, as I've previously stated
an entire page can be zero'd out, cache bypassed on miss, in 4400
cycles even when the L2 cache misses for the whole page.

That would add less to rescheduling latency than that
obtained from simply taking a hardware interrupt.

  reply	other threads:[~2004-08-12  1:02 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-08-11 23:15 clear_user_highpage() David S. Miller
2004-08-11 23:31 ` clear_user_highpage() Benjamin Herrenschmidt
2004-08-11 23:55   ` clear_user_highpage() David S. Miller
2004-08-12  0:03     ` clear_user_highpage() Benjamin Herrenschmidt
2004-08-12  1:18       ` clear_user_highpage() William Lee Irwin III
2004-08-12  2:11       ` clear_user_highpage() Andi Kleen
2004-08-12  9:23         ` clear_user_highpage() Martin Schwidefsky
2004-08-11 23:46 ` clear_user_highpage() Linus Torvalds
2004-08-11 23:53   ` clear_user_highpage() David S. Miller
2004-08-12  0:00     ` clear_user_highpage() Linus Torvalds
2004-08-12  0:06       ` clear_user_highpage() Benjamin Herrenschmidt
2004-08-12  0:24         ` clear_user_highpage() David S. Miller
2004-08-12  0:23       ` clear_user_highpage() David S. Miller
2004-08-12  1:46         ` clear_user_highpage() Linus Torvalds
2004-08-12  2:51           ` clear_user_highpage() David S. Miller
2004-08-16  1:58         ` clear_user_highpage() Paul Mackerras
2004-08-12  2:08       ` clear_user_highpage() Andi Kleen
2004-08-12  2:45         ` clear_user_highpage() David S. Miller
2004-08-12  9:09           ` clear_user_highpage() Andi Kleen
2004-08-12 19:50             ` clear_user_highpage() David S. Miller
2004-08-12 20:00               ` clear_user_highpage() Andi Kleen
2004-08-12 20:30                 ` clear_user_highpage() David S. Miller
2004-08-12 21:34               ` clear_user_highpage() Matthew Wilcox
2004-08-13  8:16                 ` clear_user_highpage() David Mosberger
2004-08-12  0:00   ` clear_user_highpage() Benjamin Herrenschmidt
2004-08-12  0:21     ` clear_user_highpage() Linus Torvalds
2004-08-12  0:46   ` clear_user_highpage() William Lee Irwin III
2004-08-12  1:01     ` David S. Miller [this message]
2004-08-12  2:18     ` clear_user_highpage() Linus Torvalds
2004-08-12  2:43       ` clear_user_highpage() David S. Miller
2004-08-12  4:19         ` clear_user_highpage() Linus Torvalds
2004-08-12  4:46           ` clear_user_highpage() William Lee Irwin III
2004-08-15  6:22             ` clear_user_highpage() Andrew Morton
2004-08-15  6:38               ` clear_user_highpage() William Lee Irwin III
2004-08-12  2:57       ` clear_user_highpage() David S. Miller
2004-08-12  3:20       ` clear_user_highpage() William Lee Irwin III
2004-08-13 21:41       ` clear_user_highpage() David S. Miller
2004-08-16 13:00         ` clear_user_highpage() David Mosberger
2004-08-22 19:51           ` clear_user_highpage() Linus Torvalds
2005-09-17 19:01             ` clear_user_highpage() Andi Kleen
2005-09-17 19:16               ` clear_user_highpage() Andi Kleen

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=20040811180122.428a9e61.davem@redhat.com \
    --to=davem@redhat.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=torvalds@osdl.org \
    --cc=wli@holomorphy.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