From mboxrd@z Thu Jan 1 00:00:00 1970 From: jlm_devel Date: Wed, 30 Jun 2004 11:57:17 +0000 Subject: Re: How to notify app of changed cpu/mem/io node configuration? Message-Id: <40E2AB64.5030306@laposte.net> List-Id: References: <20040628173808.04718b83.pj@sgi.com> In-Reply-To: <20040628173808.04718b83.pj@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org Paul Jackson wrote: >>But speaking with another OS which uses this approach, they found that >>vendors preferred the "run a script" approach anyway >> >> > >Why are the "script" and the "signal" exclusive? We seem to need both. > >I'd expect that the 'batch manager' or such would want a "script" of its >choosing executed, as you describe. > >But I also expect that a signal mechanism is required to deliver notice: > > from: the system service or its script (a batch manager, for example) > > to: the target task (a long running Fortran job, for example) > >that some special code linked in the target task needs to make sense of >the situation and invoke the appropriate mbind/set_mempolicy calls. > >Perhaps that "other OS" didn't have the difficulty we have of having to >get the target task to issue a call or two on its own behalf that can >not be issued 'by proxy'. > > > >>The real killer was that we can't add signals without breaking glibc, >> >> > >Yeah - I agree. Don't count on glibc for anything. Hence no new >signals, and expect to be overloading an existing signal for these >purposes, if it comes to that. > > > I'm not uptodate but if Icorrectly remember hotplug executes scripts when recieving an event from the kernel.... nothing prevent then to create a script that do for PID in $(ls /var/run/hotplug/signals); do kill -10 $PID; done which will send a SIGUSR1 to any process listed in /var/run/hotplug/signals more you can write a small aplication using POSIX extended signal to pass some value to the processes..... (by the way I perfer this method rather than DBUS.... because this is more "standard" and don't create again the wheel) ------------------------------------------------------- This SF.Net email sponsored by Black Hat Briefings & Training. Attend Black Hat Briefings & Training, Las Vegas July 24-29 - digital self defense, top technical experts, no vendor pitches, unmatched networking opportunities. Visit www.blackhat.com _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel