Messages in this thread | | | Date | Sun, 13 Jul 2008 01:25:39 +0200 | From | "Dmitry Adamushko" <> | Subject | Re: current linux-2.6.git: cpusets completely broken |
| |
2008/7/13 Dmitry Adamushko <dmitry.adamushko@gmail.com>: > 2008/7/13 Linus Torvalds <torvalds@linux-foundation.org>: >> >>> (A little pet horse for the occasion: Testing can show the presence of >>> errors, but not their absence. But that's a different story.) >> >> Absolutely. Which is actually why I prefer my patch. I think it fixes - in >> general - the issue of CPU migration migrating tasks back to the CPU that >> we're taking down. >> >> The other patches seem to work around just the problem that _triggers_ the >> bug. They don't actually make it impossible to migrate to a CPU that is >> getting shut down - they just try to avoid the particular sequence that >> made it happen for you. > > Well, they try to make sched-domains consistent for all possible > cases, not just any particular case. So no, they don't allow a > possibility to leave tasks on a dead CPU (unless there is another > bug). > > With your patch (and a cpusets :: hotplug handler from the current > -git) sched-domains are still broken and they are used in a number of > places. So why keep them at all? > > I'm really surprised that Vegard says this "cpu_active_map" patch > alone fixes the problem. > > With your modifications of common_cpu_mem_hotplug_unplug() - yes
No, not even with your modifications of common_mem_hotplug_unplug().
- if (phase == CPU_DYING || phase == CPU_DYING_FROZEN) + if (phase == CPU_DYING || phase == CPU_DYING_FROZEN || + phase == CPU_UP_PREPARE || phase == CPU_UP_PREPARE_FROZEN) return NOTIFY_DONE;
You should have added "phase == CPU_DOWN_PREPARE || phase == CPU_DOWN_PREPARE_FROZEN" additionally. So I'm really surprised by Vegard's assertion :-)
but > then it will work even without "cpu_active_map". > > (ok, unless I'm really blind at this late hour so please direct me to > the right way :-) > > >> >> Linus >> > > > -- > Best regards, > Dmitry Adamushko >
-- Best regards, Dmitry Adamushko
| |