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| author | Ian Campbell <ian.campbell@citrix.com> | 2010-07-29 11:16:35 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2010-07-29 13:24:58 +0200 |
| commit | 4877c737283813bdb4bebfa3168c1585f6e3a8ca (patch) | |
| tree | e46a3a9f3f0c2f91f955dba87e200a025fd6f488 /kernel | |
| parent | ba461f094bab2dc09487816b9dfce845796b259d (diff) | |
| download | blackbird-op-linux-4877c737283813bdb4bebfa3168c1585f6e3a8ca.tar.gz blackbird-op-linux-4877c737283813bdb4bebfa3168c1585f6e3a8ca.zip | |
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 <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions
