From: Paul Marquis <pmarquis@iname.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: select() bug
Date: Thu, 02 Nov 2000 17:53:48 -0500 [thread overview]
Message-ID: <3A01F07C.1DB597CE@iname.com> (raw)
In-Reply-To: <E13rSpZ-0001z2-00@the-village.bc.nu>
I guess in theory, you're right, though if a write() could succeed,
shouldn't select() say that it would?
And this assumes you're calling select() with a timeout. In Apache,
the caretaker process wakes up periodically and polls the pipe with a
timeout of zero. If it gets back the pipe is not writable, it kills
the process. With this false negative situation, this is a bad thing.
Alan Cox wrote:
>
> > that are log file handlers are dead. If select() reports it can't
> > write immediately, Apache terminates and restarts the child process,
> > creating unnecessary load on the system.
>
> Is there anything saying that select has to report ready the instant a byte
> would fit. Certainly its better for performance to reduce the context switch
> rate by encouraging blocking
--
Paul Marquis
pmarquis@iname.com
If it's tourist season, why can't we shoot them?
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next prev parent reply other threads:[~2000-11-02 22:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-11-02 22:11 select() bug Paul Marquis
2000-11-02 22:27 ` Alan Cox
2000-11-02 22:42 ` Richard B. Johnson
2000-11-02 22:58 ` Paul Marquis
2000-11-03 0:53 ` Richard B. Johnson
2000-11-03 5:00 ` Paul Marquis
2000-11-03 13:05 ` Richard B. Johnson
2000-11-02 22:53 ` Paul Marquis [this message]
2000-11-02 22:58 ` Alan Cox
2000-11-02 23:08 ` Paul Marquis
2000-11-02 23:20 ` Alan Cox
2000-11-02 23:44 ` Paul Marquis
2000-11-02 23:53 ` H. Peter Anvin
2000-11-02 23:46 ` David S. Miller
2000-11-03 0:04 ` H. Peter Anvin
2000-11-02 23:52 ` David S. Miller
2000-11-03 0:13 ` H. Peter Anvin
2000-11-03 0:05 ` David S. Miller
2000-11-03 0:38 ` H. Peter Anvin
2000-11-03 0:01 ` Alan Cox
2000-11-02 23:55 ` Alan Cox
2000-11-03 5:52 ` dean gaudet
2000-11-03 7:05 ` Marc Lehmann
-- strict thread matches above, loose matches on Subject: below --
2000-11-05 16:14 Stanislav Meduna
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