From: David Chinner <dgc@sgi.com>
To: Jarek Poplawski <jarkao2@o2.pl>
Cc: David Chinner <dgc@sgi.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH -mm] workqueue: debug possible endless loop in cancel_rearming_delayed_work
Date: Fri, 20 Apr 2007 21:01:19 +1000 [thread overview]
Message-ID: <20070420110119.GS32602149@melbourne.sgi.com> (raw)
In-Reply-To: <20070420102157.GD1695@ff.dom.local>
On Fri, Apr 20, 2007 at 12:21:57PM +0200, Jarek Poplawski wrote:
> On Fri, Apr 20, 2007 at 06:53:54PM +1000, David Chinner wrote:
> ...
> > Yes, after spending another two hours working out why my fix was
> > then hanging in cancel_rearming_delayed_work() I was a little bit
> > annoyed at the now obviously misleading comment. Five minutes later
>
> I agree with your feelings, but strictly speaking it's not "obviously
> misleading":
>
> " * cancel_rearming_delayed_work - reliably kill off a delayed
> keventd work whose handler rearms the delayed work."
" This is not reliable if the handler rearms itself conditionally
and it is restarted by external means."
> And all your rearmed works were, probably, reliably killed!
Yeah, it's the ones that weren't that we the problem ;)
> > I'd fixed the bug properly. A better comment would have saved me two
> > hours of wasted time.....
>
> It seems to be an Achilles' heel of linux...
Too true....
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
next prev parent reply other threads:[~2007-04-20 11:01 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-19 6:54 [PATCH -mm] workqueue: debug possible endless loop in cancel_rearming_delayed_work Jarek Poplawski
2007-04-19 7:32 ` Ingo Molnar
2007-04-19 8:28 ` Jarek Poplawski
2007-04-19 14:48 ` David Chinner
2007-04-19 14:46 ` David Chinner
2007-04-20 8:13 ` Jarek Poplawski
2007-04-20 8:53 ` David Chinner
2007-04-20 10:21 ` Jarek Poplawski
2007-04-20 11:01 ` David Chinner [this message]
2007-04-20 12:12 ` [PATCH] workqueue: cancel_rearming_delayed_work/workqueue usage warning Jarek Poplawski
2007-04-20 17:23 ` Oleg Nesterov
2007-04-23 9:41 ` Jarek Poplawski
2007-04-19 17:07 ` [PATCH -mm] workqueue: debug possible endless loop in cancel_rearming_delayed_work Chuck Ebbert
2007-04-20 7:14 ` Jarek Poplawski
-- strict thread matches above, loose matches on Subject: below --
2007-04-20 11:09 Jarek Poplawski
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