From: Oleg Nesterov Date: Mon, 15 Mar 2010 09:10:27 +0000 (+0100) Subject: sched: Make select_fallback_rq() cpuset friendly X-Git-Tag: v2.6.35-rc1~521^2~23 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9084bb8246ea935b98320554229e2f371f7f52fa;p=pandora-kernel.git sched: Make select_fallback_rq() cpuset friendly Introduce cpuset_cpus_allowed_fallback() helper to fix the cpuset problems with select_fallback_rq(). It can be called from any context and can't use any cpuset locks including task_lock(). It is called when the task doesn't have online cpus in ->cpus_allowed but ttwu/etc must be able to find a suitable cpu. I am not proud of this patch. Everything which needs such a fat comment can't be good even if correct. But I'd prefer to not change the locking rules in the code I hardly understand, and in any case I believe this simple change make the code much more correct compared to deadlocks we currently have. Signed-off-by: Oleg Nesterov Signed-off-by: Peter Zijlstra LKML-Reference: <20100315091027.GA9155@redhat.com> Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed