From: Ian Campbell Date: Thu, 29 Jul 2010 10:16:35 +0000 (+0100) Subject: xen: Do not suspend IPI IRQs. X-Git-Tag: v2.6.36-rc1~513^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4877c737283813bdb4bebfa3168c1585f6e3a8ca;p=pandora-kernel.git xen: Do not suspend IPI IRQs. In general the semantics of IPIs are that they are are expected to continue functioning after dpm_suspend_noirq(). Specifically I have seen a deadlock between the callfunc IPI and the stop machine used by xen's do_suspend() routine. If one CPU has already called dpm_suspend_noirq() then there is a window where it can be sent a callfunc IPI before all the other CPUs have entered stop_cpu(). If this happens then the first CPU ends up spinning in stop_cpu() waiting for the other to rendezvous in state STOPMACHINE_PREPARE while the other is spinning in csd_lock_wait(). Signed-off-by: Ian Campbell Cc: Jeremy Fitzhardinge Cc: xen-devel@lists.xensource.com LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com> Signed-off-by: Thomas Gleixner --- Reading git-diff-tree failed