linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Glauber Costa <glommer@parallels.com>
Cc: linux-kernel@vger.kernel.org, paul@paulmenage.org,
	lizf@cn.fujitsu.com, daniel.lezcano@free.fr,
	jbottomley@parallels.com
Subject: Re: [RFD 1/9] Change cpustat fields to an array.
Date: Tue, 27 Sep 2011 23:00:52 +0200	[thread overview]
Message-ID: <1317157252.21836.3.camel@twins> (raw)
In-Reply-To: <1316816432-9237-2-git-send-email-glommer@parallels.com>

On Fri, 2011-09-23 at 19:20 -0300, Glauber Costa wrote:
>  /* Must have preemption disabled for this to be meaningful. */
> -#define kstat_this_cpu __get_cpu_var(kstat)
> +#define kstat_this_cpu this_cpu_ptr(task_group_kstat(current))

This just lost you a debug check, the former would whinge when called
without preemption, the new one wont. Its part of the this_cpu feature
set to make debugging impossible.

> +#else
> +#define kstat_cpu(cpu) per_cpu(kstat, cpu)
> +#define kstat_this_cpu (&__get_cpu_var(kstat))
> +#endif
>  
>  extern unsigned long long nr_context_switches(void);
>  
> @@ -52,8 +62,8 @@ struct irq_desc;
>  static inline void kstat_incr_irqs_this_cpu(unsigned int irq,
>                                             struct irq_desc *desc)
>  {
> -       __this_cpu_inc(kstat.irqs[irq]);
> -       __this_cpu_inc(kstat.irqs_sum);
> +       kstat_this_cpu->irqs[irq]++;
> +       kstat_this_cpu->irqs_sum++;

It might be worth looking at the asm output of that, I think you made it
worse, but I'm not quite sure how smart gcc is, it might just figure out
what you meant.

>  } 

  reply	other threads:[~2011-09-27 21:01 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-23 22:20 [RFD 0/9] per-cgroup /proc/stat statistics Glauber Costa
2011-09-23 22:20 ` [RFD 1/9] Change cpustat fields to an array Glauber Costa
2011-09-27 21:00   ` Peter Zijlstra [this message]
2011-09-28 15:13     ` Glauber Costa
2011-09-28 15:23       ` Peter Zijlstra
2011-09-28 18:19     ` Glauber Costa
2011-09-28 19:09       ` Peter Zijlstra
2011-09-28 20:04         ` Glauber Costa
2011-10-01 17:47         ` Glauber Costa
2011-09-27 21:03   ` Peter Zijlstra
2011-09-28 15:14     ` Glauber Costa
2011-09-23 22:20 ` [RFD 2/9] Move /proc/stat logic inside sched.c Glauber Costa
2011-09-23 22:20 ` [RFD 3/9] Display /proc/stat information per cgroup Glauber Costa
2011-09-27 17:01   ` Balbir Singh
2011-09-27 18:42     ` Glauber Costa
2011-09-27 22:21       ` Peter Zijlstra
2011-09-28 15:22         ` Glauber Costa
2011-09-28 15:23         ` Glauber Costa
2011-09-27 21:48   ` Peter Zijlstra
2011-09-28 15:14     ` Glauber Costa
2011-09-27 21:52   ` Peter Zijlstra
2011-09-28 15:15     ` Glauber Costa
2011-09-23 22:20 ` [RFD 4/9] Make total_forks per-cgroup Glauber Costa
2011-09-27 22:00   ` Peter Zijlstra
2011-09-28  8:13     ` Martin Schwidefsky
2011-09-28 10:35       ` Peter Zijlstra
2011-09-28 12:42         ` Martin Schwidefsky
2011-09-28 12:53           ` Peter Zijlstra
2011-09-28 15:29             ` Glauber Costa
2011-09-28 15:33               ` Peter Zijlstra
2011-09-28 15:35                 ` Glauber Costa
2011-09-28 15:37                   ` Peter Zijlstra
2011-09-28 15:39                     ` Glauber Costa
2011-09-28 15:28           ` Glauber Costa
2011-09-28 15:27         ` Glauber Costa
2011-09-28 15:26       ` Glauber Costa
2011-09-23 22:20 ` [RFD 5/9] per-cgroup boot time Glauber Costa
2011-09-23 22:20 ` [RFD 6/9] Report steal time for cgroup Glauber Costa
2011-09-23 22:20 ` [RFD 7/9] provide a version of cpuacct statistics inside cpu cgroup Glauber Costa
2011-09-23 22:20 ` [RFD 8/9] provide a version of cpuusage " Glauber Costa
2011-09-23 22:20 ` [RFD 9/9] Change CPUACCT to default n Glauber Costa
2011-09-27 22:11 ` [RFD 0/9] per-cgroup /proc/stat statistics Peter Zijlstra
2011-09-28 15:21   ` Glauber Costa
2011-09-28 15:27     ` Peter Zijlstra

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=1317157252.21836.3.camel@twins \
    --to=a.p.zijlstra@chello.nl \
    --cc=daniel.lezcano@free.fr \
    --cc=glommer@parallels.com \
    --cc=jbottomley@parallels.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizf@cn.fujitsu.com \
    --cc=paul@paulmenage.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).