Re: [PATCH 2.6.25-4] getdelays.c: signal handling for log rotation

From: Scott Wiersdorf
Date: Fri Jun 06 2008 - 17:05:45 EST


On Fri, Jun 06, 2008 at 03:59:09PM +0200, Andi Kleen wrote:
> Scott Wiersdorf <scott@xxxxxxxxxxxx> writes:
>
> > This adds a USR1 signal handler to getdelays.c, which causes getdelays
> > to close its logfile and reopen it (if '-w logfile' is
> > specified). This is useful in situations when getdelays is running for
> > a long time (i.e, the log file growing) and you need to rotate the
> > logs but don't want to lose any log data.
>
> You could do the same by sending SIGSTOP; copy file; truncate file; SIGCONT

Actually, I was wrong in my previous reply. Sorry for my error. The
above will work fine (no data loss; I guess the data queues somewhere
in some magic way?)

I still think a single handler is elegant enough though, and works
better with many log rotation systems that want to send a single
signal to a pid (it's what we need where I'm working now, hence the
patch).

Scott
--
Scott Wiersdorf
<scott@xxxxxxxxxxxx>
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