From: David Woodhouse <dwmw2@infradead.org>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: davidm@hpl.hp.com, Alan Cox <alan@lxorguk.ukuu.org.uk>,
linux-kernel@vger.kernel.org, davidm@napali.hpl.hp.com
Subject: Re: adjust prefetch in free_one_pgd()
Date: Sat, 03 Aug 2002 17:59:49 +0100 [thread overview]
Message-ID: <17304.1028393989@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0208020844000.18265-100000@home.transmeta.com>
torvalds@transmeta.com said:
> > I thought the prefetches API intended this to be a safe operation?
> Well, any _sane_ prefetch API would be safe.
> However, there is known-broken hardware out there, in which a prefetch
> from IO space will kill the machine.
If you prefetch off the end of your object, and the thing you end up
prefetching is a DMA buffer which we'd just nuked from our cache to allow
the device to DMA into it, something's going to be unhappy regardless of
whether your prefetch faults or not.
--
dwmw2
next prev parent reply other threads:[~2002-08-03 16:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-08-02 0:12 adjust prefetch in free_one_pgd() David Mosberger
2002-08-02 13:04 ` Alan Cox
2002-08-02 15:39 ` David Mosberger
2002-08-02 15:46 ` Linus Torvalds
2002-08-02 15:56 ` Dave Jones
2002-08-02 15:59 ` Linus Torvalds
2002-08-02 16:04 ` Dave Jones
2002-08-02 17:49 ` Alan Cox
2002-08-02 16:38 ` David Mosberger
2002-08-02 17:58 ` Alan Cox
2002-08-02 16:53 ` David Mosberger
2002-08-03 16:59 ` David Woodhouse [this message]
2002-08-03 17:22 ` Linus Torvalds
2002-08-03 17:39 ` David Woodhouse
2002-08-03 19:36 ` Linus Torvalds
2002-08-03 22:03 ` David Woodhouse
2002-08-03 22:40 ` Linus Torvalds
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=17304.1028393989@redhat.com \
--to=dwmw2@infradead.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=davidm@hpl.hp.com \
--cc=davidm@napali.hpl.hp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@transmeta.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 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.