From: Shai Fultheim Date: Thu, 19 Apr 2012 22:12:32 +0000 (+0300) Subject: x86: Conditionally update time when ack-ing pending irqs X-Git-Tag: v3.5-rc1~139^2~7 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=42fa4250436304d4650fa271f37671f6cee24e08;p=karo-tx-linux.git x86: Conditionally update time when ack-ing pending irqs On virtual environments, apic_read could take a long time. As a result, under certain conditions the ack pending loop may exit without any queued irqs left, but after more than one second. A warning will be printed needlessly in this case. If the loop is about to exit regardless of max_loops, don't update it. Signed-off-by: Shai Fultheim [ rebased and reworded the commit message] Signed-off-by: Ido Yariv Acked-by: Thomas Gleixner Link: http://lkml.kernel.org/r/1334873552-31346-1-git-send-email-ido@wizery.com Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index edc24480469f..3beab627190e 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1325,11 +1325,13 @@ void __cpuinit setup_local_APIC(void) acked); break; } - if (cpu_has_tsc) { - rdtscll(ntsc); - max_loops = (cpu_khz << 10) - (ntsc - tsc); - } else - max_loops--; + if (queued) { + if (cpu_has_tsc) { + rdtscll(ntsc); + max_loops = (cpu_khz << 10) - (ntsc - tsc); + } else + max_loops--; + } } while (queued && max_loops > 0); WARN_ON(max_loops <= 0);