On Thursday 07 May 2009, David Rientjes wrote: > On Thu, 7 May 2009, Rafael J. Wysocki wrote: > > > OK, let's try with __GFP_NO_OOM_KILL first. If there's too much disagreement, > > I'll use the freezer-based approach instead. > > > > Third time I'm going to suggest this, and I'd like a response on why it's > not possible instead of being ignored. > > All of your tasks are in D state other than kthreads, right? That means > they won't be in the oom killer (thus no zones are oom locked), so you can > easily do this > > struct zone *z; > for_each_populated_zone(z) > zone_set_flag(z, ZONE_OOM_LOCKED); > > and then > > for_each_populated_zone(z) > zone_clear_flag(z, ZONE_OOM_LOCKED); > > The serialization is done with trylocks so this will never invoke the oom > killer because all zones in the allocator's zonelist will be oom locked. Well, that might have been a good idea if it actually had worked. :-( > Why does this not work for you? If I set image_size to something below "hard core working set" + totalreserve_pages, preallocate_image_memory() hangs the box (please refer to the last patch I sent, http://patchwork.kernel.org/patch/22423/). However, with the freezer-based disabling of the OOM killer it doesn't hang under the same test conditions. The difference appears to be that using your approach makes __alloc_pages_internal() loop forever between the !try_set_zone_oom() test and restart:, while it should go to nopage: in that situation. So, I think I'll stick to the Andrew's approach with using __GFP_NO_OOM_KILL. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
