path: root/arch/x86
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authorDavid Vrabel <david.vrabel@citrix.com>2014-08-07 17:06:06 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2014-08-11 11:59:34 +0100
commit8d5999df35314607c38fbd6bdd709e25c3a4eeab (patch)
tree38fcf034dcaba3286bd00fe9ac662876cf7aa893 /arch/x86
parentac80c770032c04d37d3f3f74249df66c7329cf38 (diff)
x86/xen: resume timer irqs early
If the timer irqs are resumed during device resume it is possible in certain circumstances for the resume to hang early on, before device interrupts are resumed. For an Ubuntu 14.04 PVHVM guest this would occur in ~0.5% of resume attempts. It is not entirely clear what is occuring the point of the hang but I think a task necessary for the resume calls schedule_timeout(), waiting for a timer interrupt (which never arrives). This failure may require specific tasks to be running on the other VCPUs to trigger (processes are not frozen during a suspend/resume if PREEMPT is disabled). Add IRQF_EARLY_RESUME to the timer interrupts so they are resumed in syscore_resume(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'arch/x86')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 7b78f88c170..5718b0b58b6 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -444,7 +444,7 @@ void xen_setup_timer(int cpu)
irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt,
name, NULL);
(void)xen_set_irq_priority(irq, XEN_IRQ_PRIORITY_MAX);