All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Tejun Heo <tj@kernel.org>,
	computersforpeace@gmail.com, Ingo Molnar <mingo@kernel.org>,
	der.herr@hofr.at
Subject: Re: complete_all and "forever" completions
Date: Wed, 26 Oct 2016 17:46:47 +0200	[thread overview]
Message-ID: <20161026154647.GJ3157@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20161026154213.GD3117@twins.programming.kicks-ass.net>

On Wed, Oct 26, 2016 at 05:42:13PM +0200, Peter Zijlstra wrote:

> Does something like so work?

try_wait_for_completion() would need a similar change.

> ---
>  kernel/sched/completion.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
> index 8d0f35debf35..5deab9c789df 100644
> --- a/kernel/sched/completion.c
> +++ b/kernel/sched/completion.c
> @@ -51,7 +51,7 @@ void complete_all(struct completion *x)
>  	unsigned long flags;
>  
>  	spin_lock_irqsave(&x->wait.lock, flags);
> -	x->done += UINT_MAX/2;
> +	x->done = UINT_MAX/2;
>  	__wake_up_locked(&x->wait, TASK_NORMAL, 0);
>  	spin_unlock_irqrestore(&x->wait.lock, flags);
>  }
> @@ -79,7 +79,10 @@ do_wait_for_common(struct completion *x,
>  		if (!x->done)
>  			return timeout;
>  	}
> -	x->done--;
> +
> +	if (x->done != UINT_MAX/2)
> +		x->done--;
> +
>  	return timeout ?: 1;
>  }
>  

  reply	other threads:[~2016-10-26 15:46 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-25 22:30 complete_all and "forever" completions Dmitry Torokhov
2016-10-26  8:45 ` Peter Zijlstra
2016-10-26  9:15   ` Nicholas Mc Guire
2016-10-27  9:51     ` Daniel Wagner
2016-10-26 12:10   ` Dmitry Torokhov
2016-10-26 15:42     ` Peter Zijlstra
2016-10-26 15:46       ` Peter Zijlstra [this message]
2016-10-26 17:12       ` Nicholas Mc Guire
2016-10-26 17:20         ` Dmitry Torokhov
2016-10-26 18:23       ` Dmitry Torokhov

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=20161026154647.GJ3157@twins.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=computersforpeace@gmail.com \
    --cc=der.herr@hofr.at \
    --cc=dmitry.torokhov@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=tj@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.