The Linux Kernel Mailing List
 help / color / mirror / Atom feed
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 2/3] nohz: Convert tick dependency mask to atomic_t
Date: Fri, 25 Mar 2016 15:56:13 +0100	[thread overview]
Message-ID: <20160325145612.GB16488@lerouge> (raw)
In-Reply-To: <20160325085202.GB15235@gmail.com>

On Fri, Mar 25, 2016 at 09:52:02AM +0100, Ingo Molnar wrote:
> > diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h
> > index eb4e325..bf38226 100644
> > --- a/kernel/time/tick-sched.h
> > +++ b/kernel/time/tick-sched.h
> > @@ -60,7 +60,7 @@ struct tick_sched {
> >  	u64				next_timer;
> >  	ktime_t				idle_expires;
> >  	int				do_timer_last;
> > -	unsigned long			tick_dep_mask;
> > +	atomic_t			tick_dep_mask;
> >  };
> >  
> >  extern struct tick_sched *tick_get_tick_sched(int cpu);
> 
> Yeah, so I really like this interface, because it makes it really, really obvious 
> that only atomic_t-compatible operations can be used on the value. It's a common 
> bug to have a long, operated on atomically via bitops - and then occasionally 
> operated on in a non-atomic fashion, or used without taking ordering into account. 
> Such bugs are quite hard to find.
> 
> This change also shrinks the mask from long to int, which is an another bonus, and 
> which addresses the other objection Linus had.

Thanks, I much prefer it that way too!

Should I do a pull request or can I let you apply these?

  reply	other threads:[~2016-03-25 14:56 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-24 14:37 [PATCH 0/3] nohz: Convert tick dependency mask to atomic_t Frederic Weisbecker
2016-03-24 14:37 ` [PATCH 1/3] atomic: Introduce atomic_fetch_or Frederic Weisbecker
2016-03-29 10:36   ` [tip:core/urgent] locking/atomic: Introduce atomic_fetch_or() tip-bot for Frederic Weisbecker
2016-03-24 14:38 ` [PATCH 2/3] nohz: Convert tick dependency mask to atomic_t Frederic Weisbecker
2016-03-25  8:52   ` Ingo Molnar
2016-03-25 14:56     ` Frederic Weisbecker [this message]
2016-03-29 10:37   ` [tip:core/urgent] timers/nohz: " tip-bot for Frederic Weisbecker
2016-03-24 14:38 ` [PATCH 3/3] Revert "atomic: Export fetch_or()" Frederic Weisbecker
2016-03-29 10:37   ` [tip:core/urgent] locking/atomic, sched: Unexport fetch_or() tip-bot for Frederic Weisbecker
2016-03-25  8:48 ` [PATCH 0/3] nohz: Convert tick dependency mask to atomic_t Ingo Molnar
2016-03-25 13:17   ` Frederic Weisbecker
2016-03-29  9:44     ` Ingo Molnar
2016-03-29 12:23       ` Linus Torvalds
2016-03-29 12:59         ` Ingo Molnar
2016-03-29 13:05           ` Ingo Molnar
2016-03-29 13:08             ` Frederic Weisbecker
2016-03-31  6:54               ` Ingo Molnar
2016-03-31  9:20                 ` Peter Zijlstra
2016-03-31 13:18                   ` Ingo Molnar
2016-03-29 13:14             ` Ingo Molnar

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=20160325145612.GB16488@lerouge \
    --to=fweisbec@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.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