All of lore.kernel.org
 help / color / mirror / Atom feed
From: Keith Whitwell <keith@tungstengraphics.com>
To: george anzinger <george@mvista.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: linux-2.5.18: DRM + cmpxchg issues
Date: Wed, 29 May 2002 08:23:27 +0100	[thread overview]
Message-ID: <3CF481EF.9010106@tungstengraphics.com> (raw)
In-Reply-To: <3CF33C10.1090302@tungstengraphics.com> <3CF427E4.79042F@mvista.com>

george anzinger wrote:
> Keith Whitwell wrote:
> 
>>Adam,
>>
>>I expect the answer is that we need to dig out the old one.
>>
>>Previously I don't think the full cmpxchg semantics werere required unless the
>>box is smp -- there's no case where atomic operations are required for
>>hardware interaction, for example.  ...
>>
>>Probably this changed with preempt, though, so we need one even on UP boxes...
>>
>>
> I can not think of any reason to need a lock or atomic
> operation because of preempt.  Even the management of the
> preempt on/off flags at most requires memory barriers, even
> in SMP boxen.  Do you have an example?

No, I was just pointing out grey areas in my own knowledge.

Keith


  reply	other threads:[~2002-05-29  7:24 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-05-28  8:13 linux-2.5.18: DRM + cmpxchg issues Keith Whitwell
2002-05-29  0:59 ` george anzinger
2002-05-29  7:23   ` Keith Whitwell [this message]
  -- strict thread matches above, loose matches on Subject: below --
2002-05-26  8:32 Adam J. Richter

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=3CF481EF.9010106@tungstengraphics.com \
    --to=keith@tungstengraphics.com \
    --cc=george@mvista.com \
    --cc=linux-kernel@vger.kernel.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.