From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [RFC] sleepy linux Date: Tue, 8 Jan 2008 17:37:44 +0100 Message-ID: <20080108163744.GB13746@elte.hu> References: <20071225230731.GA29030@elf.ucw.cz> <20071230111552.GA8578@elte.hu> <20080105215123.GA21565@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20080105215123.GA21565@elf.ucw.cz> Sender: linux-kernel-owner@vger.kernel.org To: Pavel Machek Cc: kernel list , Linux-pm mailing list , "Rafael J. Wysocki" List-Id: linux-pm@vger.kernel.org * Pavel Machek wrote: > > a quick feature request: could you please make the wake-on-RTC > > capability generic and add a CONFIG_DEBUG_SUSPEND_ON_RAM=y config > > option (disabled by default) that does a short 1-second > > suspend-to-RAM sequence upon bootup? That way we could test s2ram > > automatically (which is a MUCH needed feature for automated > > regression testing and automatic bisection). In addition, some sort > > of 'suspend for N seconds' /sys or /dev/rtc capability would be nice > > as well. > > Hmm, are you sure it is good idea to do this from kernel? I guess this > is better done from script... i have this low-prio effort to make all self-checks automatically available via 'make randconfig' as well, for all features that have no natural exposure during normal bootup. So far we've got rcutorture, kprobes-check, locking/lockdep-self-test and a handful of others. External scripts tend to go out of sync and LTP takes way too much time to finish. > > btw., how far are you from having a working prototype? > > SCSI/SATA issues stop me just now, but even if I get that to work, it > will be extremely disgusting hack... and it is unclear how to do it > nicely :-(. as long as the sleep periods are within say 10-20 seconds, and our s2ram cycle is fast and optimal enough, we could do this with networking enabled too, without dropping/stalling TCP connections left and right. (Perhaps if we could notify routers that they should batch packets for N seconds and we could turn off PHY during that time, it would be even nicer - is there any such router extension in existence?) but if it's nothing else but a s2ram debug/stress utility, that alone would be great too :-) Ingo