a strace shows it works differently
nanosleep({1, 0}, {1, 0}) = 0
fstat(3, {st_mode=S_IFREG|0600, st_size=227128, ...}) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [RT_0], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [RT_0], NULL, 8) = 0
the file is opened just once (as I expected), and tail sleeps in nanosleep
() until the file grows. I think strace isn't showing more nanosleep() as it
should be looping there. BTW what's the reason for the sigprocmask, etc?
----- Original Message -----
From: "Ignacio Vazquez-Abrams" <ignacio@openservices.net>
To: "Carlos Fernández Sanz" <cfs-lk@fulanito.nisupu.com>
Cc: <linux-kernel@vger.kernel.org>
Sent: Monday, August 20, 2001 11:00 PM
Subject: Re: Fw: select(), EOF...
> On Mon, 20 Aug 2001, Carlos Fernández Sanz wrote:
>
> > How come the process is never runnable unless there's new data in the
file?
> > If it was opening and closing the file continously it would be using
lots of
> > CPU, while it's 0 if there's no data coming.
>
> It sleep()s between close() and open().
>
> --
> Ignacio Vazquez-Abrams <ignacio@openservices.net>
>
> -
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This archive was generated by hypermail 2b29 : Thu Aug 23 2001 - 21:00:37 EST