public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: William Lee Irwin III <wli@holomorphy.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@osdl.org>, John Hawkes <hawkes@sgi.com>,
	Ray Bryant <raybry@sgi.com>, Jesse Barnes <jbarnes@engr.sgi.com>,
	lkml - Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [profile] fix timer interrupt livelock on 512x Altix
Date: Fri, 15 Oct 2004 03:43:11 -0700	[thread overview]
Message-ID: <20041015104311.GD5607@holomorphy.com> (raw)
In-Reply-To: <1097804782.22673.56.camel@localhost.localdomain>

On Tue, 2004-09-21 at 07:30, William Lee Irwin III wrote:
>> +static void __profile_flip_buffers(void *unused)
>> +{
>> +	int cpu = smp_processor_id();
>> +
>> +	per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu);
>> +}

On Fri, Oct 15, 2004 at 11:46:22AM +1000, Rusty Russell wrote:
> Please: one point of per-cpu vars is that archs can choose to hold the
> per-cpu offset in a reg, and derive smp_processor_id() from that.  By
> doing the reverse, manually, you defeat this.  How about:
> 	int *flip = __get_cpu_var(cpu_profile_flip);
> 	*flip = !*flip;

Proof once more that sustained and repeated exposure to shitty
architectures degrades intelligence. I'll send in a correction shortly.


-- wli

      reply	other threads:[~2004-10-15 10:43 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-09-20 21:30 [profile] fix timer interrupt livelock on 512x Altix William Lee Irwin III
2004-09-21  5:15 ` Andrew Morton
2004-09-21  8:42   ` William Lee Irwin III
2004-09-23  2:08     ` William Lee Irwin III
2004-10-15  1:46 ` Rusty Russell
2004-10-15 10:43   ` William Lee Irwin III [this message]

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=20041015104311.GD5607@holomorphy.com \
    --to=wli@holomorphy.com \
    --cc=akpm@osdl.org \
    --cc=hawkes@sgi.com \
    --cc=jbarnes@engr.sgi.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=raybry@sgi.com \
    --cc=rusty@rustcorp.com.au \
    /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