All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
	"Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org>,
	Steve French <sfrench-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	"J. Bruce Fields"
	<bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>,
	Neil Brown <neilb-l3A5Bk7waGM@public.gmane.org>,
	trond.myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org,
	linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC PATCH] freezer: revert 27920651fe "PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too"
Date: Tue, 1 Nov 2011 19:13:29 +0100	[thread overview]
Message-ID: <20111101181329.GA6739@redhat.com> (raw)
In-Reply-To: <20111101180601.GV18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

On 11/01, Tejun Heo wrote:
>
> Yeah yeah, Trond already pointed it out.  I forgot about the
> sigpending special case in schedule(), which I think is rather odd,

I disagree with "rather odd" ;)

We have a lot of examples of

	current->state = TASK_INTERRUPTIBLE;
	...
	if (signal_pending())
		break;
	schedule();

Without that special case in schedule() the code above becomes racy.
Just consider __wait_event_interruptible().

> Any better ideas?

Well. As a simple (probably temporary) fix, I'd suggest

	#define wait_event_freezekillable(wq, condition)
	{
		freezer_do_not_count();
		__retval = wait_event_killable(condition);
		freezer_count();
		__retval;
	}

Do you think it can work?

Oleg.

--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

WARNING: multiple messages have this Message-ID (diff)
From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Jeff Layton <jlayton@redhat.com>,
	"Rafael J. Wysocki" <rjw@sisk.pl>,
	Steve French <sfrench@samba.org>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-cifs@vger.kernel.org,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Neil Brown <neilb@suse.de>,
	trond.myklebust@netapp.com, linux-nfs@vger.kernel.org
Subject: Re: [RFC PATCH] freezer: revert 27920651fe "PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too"
Date: Tue, 1 Nov 2011 19:13:29 +0100	[thread overview]
Message-ID: <20111101181329.GA6739@redhat.com> (raw)
In-Reply-To: <20111101180601.GV18855@google.com>

On 11/01, Tejun Heo wrote:
>
> Yeah yeah, Trond already pointed it out.  I forgot about the
> sigpending special case in schedule(), which I think is rather odd,

I disagree with "rather odd" ;)

We have a lot of examples of

	current->state = TASK_INTERRUPTIBLE;
	...
	if (signal_pending())
		break;
	schedule();

Without that special case in schedule() the code above becomes racy.
Just consider __wait_event_interruptible().

> Any better ideas?

Well. As a simple (probably temporary) fix, I'd suggest

	#define wait_event_freezekillable(wq, condition)
	{
		freezer_do_not_count();
		__retval = wait_event_killable(condition);
		freezer_count();
		__retval;
	}

Do you think it can work?

Oleg.


  parent reply	other threads:[~2011-11-01 18:13 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-31 22:17 [RFC PATCH] freezer: revert 27920651fe "PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too" Tejun Heo
2011-10-31 22:17 ` Tejun Heo
     [not found] ` <20111031221743.GA18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-10-31 23:17   ` Tejun Heo
2011-10-31 23:17     ` Tejun Heo
2011-10-31 23:24   ` Rafael J. Wysocki
2011-10-31 23:24     ` Rafael J. Wysocki
2011-10-31 23:30     ` Tejun Heo
2011-11-01  0:55       ` Tejun Heo
     [not found]         ` <20111101005505.GO18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-01  8:13           ` Jeff Layton
2011-11-01  8:13             ` Jeff Layton
     [not found]             ` <20111101041337.39077229-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2011-11-01 10:59               ` Jeff Layton
2011-11-01 10:59                 ` Jeff Layton
     [not found]                 ` <20111101065958.50addab5-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2011-11-01 16:30                   ` Tejun Heo
2011-11-01 16:30                     ` Tejun Heo
     [not found]                     ` <20111101163059.GR18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-01 16:49                       ` Trond Myklebust
2011-11-01 16:49                         ` Trond Myklebust
     [not found]                         ` <1320166171.5019.1.camel-SyLVLa/KEI9HwK5hSS5vWB2eb7JE58TQ@public.gmane.org>
2011-11-01 16:55                           ` Tejun Heo
2011-11-01 16:55                             ` Tejun Heo
2011-11-01 17:59                       ` Oleg Nesterov
2011-11-01 17:59                         ` Oleg Nesterov
     [not found]                         ` <20111101175953.GB5358-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-11-01 18:06                           ` Tejun Heo
2011-11-01 18:06                             ` Tejun Heo
     [not found]                             ` <20111101180601.GV18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-01 18:13                               ` Oleg Nesterov [this message]
2011-11-01 18:13                                 ` Oleg Nesterov
     [not found]                                 ` <20111101181329.GA6739-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-11-01 18:27                                   ` Tejun Heo
2011-11-01 18:27                                     ` Tejun Heo
     [not found]                                     ` <20111101182753.GW18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-01 19:39                                       ` Oleg Nesterov
2011-11-01 19:39                                         ` Oleg Nesterov
     [not found]                                         ` <20111101193923.GA9444-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-11-01 19:46                                           ` Oleg Nesterov
2011-11-01 19:46                                             ` Oleg Nesterov
2011-11-01 21:57                                             ` Tejun Heo
     [not found]                                               ` <20111101215710.GA13803-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-02 11:42                                                 ` Jeff Layton
2011-11-02 11:42                                                   ` Jeff Layton
     [not found]                                                   ` <20111102074257.7174691c-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2011-11-02 15:13                                                     ` Oleg Nesterov
2011-11-02 15:13                                                       ` Oleg Nesterov
2011-11-02 16:23                                                 ` Oleg Nesterov
2011-11-02 16:23                                                   ` Oleg Nesterov
     [not found]                                                   ` <20111102162331.GA31947-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-11-02 23:11                                                     ` Rafael J. Wysocki
2011-11-02 23:11                                                       ` Rafael J. Wysocki
2011-11-03 11:15                                                       ` Jeff Layton
     [not found]                                                       ` <201111030011.24062.rjw-KKrjLPT3xs0@public.gmane.org>
2011-11-03 15:10                                                         ` Oleg Nesterov
2011-11-03 15:10                                                           ` Oleg Nesterov
2011-11-02 17:53                                                 ` [PATCH] wait_event_freezekillable: use freezer_do_not_count/freezer_count Oleg Nesterov
2011-11-02 17:53                                                   ` Oleg Nesterov
2011-11-03 10:42                                                   ` Jeff Layton
     [not found]                                                     ` <20111103064215.48939e1a-9yPaYZwiELC+kQycOl6kW4xkIHaj4LzF@public.gmane.org>
2011-11-03 14:13                                                       ` Tejun Heo
2011-11-03 14:13                                                         ` Tejun Heo
     [not found]                                                         ` <20111103141354.GB4417-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-03 15:27                                                           ` Jeff Layton
2011-11-03 15:27                                                             ` Jeff Layton
     [not found]                                                             ` <20111103112704.4b905bfc-xSBYVWDuneFaJnirhKH9O4GKTjYczspe@public.gmane.org>
2011-11-03 15:30                                                               ` Tejun Heo
2011-11-03 15:30                                                                 ` Tejun Heo
2011-11-01 18:26                               ` [RFC PATCH] freezer: revert 27920651fe "PM / Freezer: Make fake_signal_wake_up() wake TASK_KILLABLE tasks too" Jeff Layton
2011-11-01 18:26                                 ` Jeff Layton
     [not found]     ` <201111010024.16659.rjw-KKrjLPT3xs0@public.gmane.org>
2011-10-31 23:45       ` Steve French
2011-10-31 23:45         ` Steve French
     [not found]         ` <CAH2r5msMiG8MjhYuVv8ehqkBLKc1Av3hi+2q6zwrrXdTTa_+YQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-10-31 23:53           ` Tejun Heo
2011-10-31 23:53             ` Tejun Heo
     [not found]             ` <20111031235335.GL18855-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2011-11-01  0:02               ` Steve French
2011-11-01  0:02                 ` Steve French
2011-11-01 17:50   ` Oleg Nesterov
2011-11-01 17:50     ` Oleg Nesterov

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=20111101181329.GA6739@redhat.com \
    --to=oleg-h+wxahxf7alqt0dzr+alfa@public.gmane.org \
    --cc=bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org \
    --cc=jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
    --cc=linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=neilb-l3A5Bk7waGM@public.gmane.org \
    --cc=rjw-KKrjLPT3xs0@public.gmane.org \
    --cc=sfrench-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org \
    --cc=tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
    --cc=trond.myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.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.