From: torvalds@transmeta.com (Linus Torvalds)
To: linux-kernel@vger.kernel.org
Subject: Re: 2.4.6 possible problem
Date: Tue, 17 Jul 2001 19:24:23 +0000 (UTC) [thread overview]
Message-ID: <9j23d7$1qs$1@penguin.transmeta.com> (raw)
In-Reply-To: <3B54454B.97AA34E6@ueidaq.com> <Pine.LNX.3.95.1010717103652.1430A-100000@chaos.analogic.com>
In article <Pine.LNX.3.95.1010717103652.1430A-100000@chaos.analogic.com>,
Richard B. Johnson <root@chaos.analogic.com> wrote:
>
> ticks = 1 * HZ; /* For 1 second */
> while((ticks = interruptible_sleep_on_timeout(&wqhead, ticks)) > 0)
> ;
Don't do this.
Imagine what happens if a signal comes in and wakes you up? The signal
will continue to be pending, which will make your "sleep loop" be a busy
loop as you can never go to sleep interruptibly with a pending signal.
In short: if you have to wait for a certain time or for a certain event,
you MUST NOT USE a interruptible sleep.
If it is ok to return early due to signals or similar (which is nice -
you can allow people to kill the process), then you use an interruptible
sleep, but then you mustn't have the above kind of loop.
Linus
next prev parent reply other threads:[~2001-07-17 19:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-07-17 14:01 2.4.6 possible problem Alex Ivchenko
2001-07-17 14:46 ` Richard B. Johnson
2001-07-17 18:44 ` Alex Ivchenko
2001-07-17 18:52 ` Richard B. Johnson
2001-07-17 19:24 ` Linus Torvalds [this message]
2001-07-17 19:36 ` Richard B. Johnson
2001-07-17 19:42 ` Richard B. Johnson
2001-07-17 22:33 ` Alex Ivchenko
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