public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Venkatesh Pallipadi <venki@google.com>,
	Russell King - ARM Linux <linux@arm.linux.org.uk>,
	Mikael Pettersson <mikpe@it.uu.se>, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	John Stultz <johnstul@us.ibm.com>,
	Christoph Lameter <cl@linux-foundation.org>
Subject: Re: [BUG] 2.6.37-rc3 massive interactivity regression on ARM
Date: Fri, 10 Dec 2010 18:49:06 +0100	[thread overview]
Message-ID: <1292003346.13513.30.camel@laptop> (raw)
In-Reply-To: <1292001500.3580.268.camel@edumazet-laptop>

On Fri, 2010-12-10 at 18:18 +0100, Eric Dumazet wrote:
> Le vendredi 10 décembre 2010 à 14:47 +0100, Peter Zijlstra a écrit :

> Also irq_time_write_begin() and irq_time_write_end() could be faster
> (called for current cpu)
> 
> static inline void irq_time_write_begin(void)
> {
> 	__this_cpu_inc(irq_time_seq.sequence);
> 	smp_wmb();
> }
>  
> static inline void irq_time_write_end(void)
> {
> 	smp_wmb();
> 	__this_cpu_inc(irq_time_seq.sequence);
> }

Yeah, but that kinda defeats the purpose of having it implemented in
seqlock.h. Ideally we'd teach gcc about these long pointers and have
something like: 

  write_seqcount_begin(&this_cpu_read(irq_time_seq));

do the right thing.

  reply	other threads:[~2010-12-10 17:49 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-27 15:16 [BUG] 2.6.37-rc3 massive interactivity regression on ARM Mikael Pettersson
2010-12-05 12:32 ` Mikael Pettersson
2010-12-05 13:17   ` Russell King - ARM Linux
2010-12-05 14:19     ` Russell King - ARM Linux
2010-12-05 16:07       ` Mikael Pettersson
2010-12-05 16:21         ` Russell King - ARM Linux
2010-12-08 12:40           ` Peter Zijlstra
2010-12-08 12:55             ` Russell King - ARM Linux
2010-12-08 14:04               ` Peter Zijlstra
2010-12-08 14:28                 ` Russell King - ARM Linux
2010-12-08 14:44                   ` Peter Zijlstra
2010-12-08 15:05                     ` Russell King - ARM Linux
2010-12-08 15:43                     ` Linus Walleij
2010-12-08 20:42                     ` john stultz
2010-12-08 23:31                   ` Venkatesh Pallipadi
2010-12-09 12:52                     ` Peter Zijlstra
2010-12-09 17:43                       ` Venkatesh Pallipadi
2010-12-09 17:55                         ` Peter Zijlstra
2010-12-09 18:11                           ` Venkatesh Pallipadi
2010-12-09 18:55                             ` Peter Zijlstra
2010-12-09 22:21                               ` Venkatesh Pallipadi
2010-12-09 23:16                                 ` Peter Zijlstra
2010-12-09 23:35                                   ` Venkatesh Pallipadi
2010-12-10 10:08                                     ` Peter Zijlstra
2010-12-10 13:17                                       ` Peter Zijlstra
2010-12-10 13:27                                         ` Peter Zijlstra
2010-12-10 13:47                                           ` Peter Zijlstra
2010-12-10 16:50                                             ` Russell King - ARM Linux
2010-12-10 16:54                                               ` Peter Zijlstra
2010-12-10 17:18                                             ` Eric Dumazet
2010-12-10 17:49                                               ` Peter Zijlstra [this message]
2010-12-10 18:14                                                 ` Eric Dumazet
2010-12-10 18:39                                                   ` Christoph Lameter
2010-12-10 18:46                                                     ` Peter Zijlstra
2010-12-10 19:51                                                       ` Christoph Lameter
2010-12-10 20:07                                                         ` Peter Zijlstra
2010-12-10 20:23                                                           ` Christoph Lameter
2010-12-10 20:32                                                             ` Peter Zijlstra
2010-12-10 20:39                                                             ` Eric Dumazet
2010-12-10 20:49                                                               ` Eric Dumazet
2010-12-10 21:09                                                                 ` Christoph Lameter
2010-12-10 21:22                                                                   ` Eric Dumazet
2010-12-10 21:45                                                                     ` Christoph Lameter
2010-12-10 17:56                                             ` Russell King - ARM Linux
2010-12-10 18:10                                               ` Peter Zijlstra
2010-12-10 18:43                                                 ` Peter Zijlstra
2010-12-10 19:17                                                 ` Russell King - ARM Linux
2010-12-10 19:37                                                   ` Peter Zijlstra
2010-12-10 19:25                                                 ` Peter Zijlstra
2010-12-13 14:33                             ` Jack Daniel
2010-12-06 21:29       ` Venkatesh Pallipadi

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=1292003346.13513.30.camel@laptop \
    --to=peterz@infradead.org \
    --cc=cl@linux-foundation.org \
    --cc=eric.dumazet@gmail.com \
    --cc=johnstul@us.ibm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@arm.linux.org.uk \
    --cc=mikpe@it.uu.se \
    --cc=mingo@elte.hu \
    --cc=venki@google.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