From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [patch 0/4] Take care of cpufreq lockdep issues (take 2) Date: Fri, 3 Jul 2009 20:48:55 +0200 Message-ID: <20090703184855.GA6931@elte.hu> References: <20090703000829.735976000@intel.com> <20090703065427.GA32687@elte.hu> <7E82351C108FA840AB1866AC776AEC4669BFF052@orsmsx505.amr.corp.intel.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <7E82351C108FA840AB1866AC776AEC4669BFF052-osO9UTpF0URqS6EAlXoojrfspsVTdybXVpNB7YpNyf8@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Pallipadi, Venkatesh" Cc: Dave Jones , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "cpufreq-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "Rafael J. Wysocki" , Dave Young , Pekka Enberg , Mathieu Desnoyers , Thomas Renninger * Pallipadi, Venkatesh wrote: > > > >-----Original Message----- > >From: Ingo Molnar [mailto:mingo-X9Un+BFzKDI@public.gmane.org] > >Sent: Thursday, July 02, 2009 11:54 PM > >To: Pallipadi, Venkatesh > >Cc: Dave Jones; linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; > >cpufreq-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; > >Rafael J. Wysocki; Dave Young; Pekka Enberg; Mathieu > >Desnoyers; Thomas Renninger > >Subject: Re: [patch 0/4] Take care of cpufreq lockdep issues (take 2) > > > > > >* venkatesh.pallipadi-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote: > > > >> Since recent chanegs to ondemand and conservative governor, there > >> have been multiple reports of lockdep issues in cpufreq. Patch > >> series takes care of these problems. > >> > >> This is the next attempt following the one here, which was not a > >> complete fix. > >> http://lkml.indiana.edu/hypermail/linux/kernel/0906.3/01073.html > >> > >> I am currently running some stress tests to make sure there are no > >> issues with these patches. But, wanted to send them out for > >> review/comments/testing before I head out for the long weekend. > >> > >> If this patchset seems sane, the first patch in the patchset > >> should also get into 30.stable. > > > >Btw., FYI, because my test-systems were frequently triggering those > >bugs, i kept testing the following series from you and Mathieu in > >-tip: > > > > ecf8b04: cpufreq: Define dbs_mutex purpose and cleanup its > >usage conservative gov > > b08c597: cpufreq: Define dbs_mutex purpose and cleanup its usage > > 0807e30: cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP > >call (second call site) > > > >So that fix-series, while probably not complete (given that you sent > >a v2 series), worked well in practice and gets my: > > > > Tested-by: Ingo Molnar > > > >Is the delta between this (tested) series and your v2 version > >significant? If not it might make sense to shape it as a delta patch > >to the v1 series, if that looks clean enough - to preserve testing > >results. > > > > Thanks for testing. That earlier version even though it took care > of lockdep complaints, did not address all the race conditions > properly. The delta is significant as I had to change the approach > compared to first patchset. So, diff will not be very clean. Fair enough - these cases are when it makes sense to do a clean rebase. Ingo