From 82908a4acc2143da630162c5bebf381c6c166d45 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Thu, 7 Aug 2014 17:06:06 +0100 Subject: [PATCH] x86/xen: resume timer irqs early commit 8d5999df35314607c38fbd6bdd709e25c3a4eeab upstream. 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 Reviewed-by: Boris Ostrovsky Signed-off-by: Jiri Slaby --- arch/x86/xen/time.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index ee365895b06b..90bfa524b11c 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -445,7 +445,7 @@ void xen_setup_timer(int cpu) irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt, IRQF_DISABLED|IRQF_PERCPU| IRQF_NOBALANCING|IRQF_TIMER| - IRQF_FORCE_RESUME, + IRQF_FORCE_RESUME|IRQF_EARLY_RESUME, name, NULL); memcpy(evt, xen_clockevent, sizeof(*evt)); -- 2.11.4.GIT