From: Wei Wang <wei.wang2@amd.com>
To: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Jan Beulich <JBeulich@suse.com>, Keir Fraser <keir@xen.org>
Subject: [PATCH] acpi: Fix an incorrect code path in acpi_processor_idle()
Date: Thu, 5 Apr 2012 15:39:14 +0200 [thread overview]
Message-ID: <4F7DA082.5030503@amd.com> (raw)
Hi, There seems to be an incorrect code path in acpi_processor_idle().
ACPI_STATE_C3 code path might need to be avoided when cpu tries to enter
c2 but lapic_timer_c2_ok is not set. This bug affects some amd systems
which have c2 state available. The XenServer 6.0 performance issue[1]
should also be fixed by this patch. If it looks fine, please apply it to
unstable, 4.1 and 4.0
Thanks,
Wei
[1]
http://forums.citrix.com/thread.jspa?threadID=297461&tstart=0&start=0
# HG changeset patch
# User Wei Wang <wei.wang2@amd.com>
# Date 1333626300 -7200
# Node ID bc0e1869ba5c77e85f3ed012a979ac8061094367
# Parent d690c7e896a26c54a5ab85458824059de72d5cba
Fix an incorrect code path in acpi_processor_idle()
Signed-off-by: Wei Wang <wei.wang2@amd.com>
diff -r d690c7e896a2 -r bc0e1869ba5c xen/arch/x86/acpi/cpu_idle.c
--- a/xen/arch/x86/acpi/cpu_idle.c Thu Apr 05 11:06:03 2012 +0100
+++ b/xen/arch/x86/acpi/cpu_idle.c Thu Apr 05 13:45:00 2012 +0200
@@ -466,8 +466,8 @@ static void acpi_processor_idle(void)
local_irq_enable();
/* Compute time (ticks) that we were actually asleep */
sleep_ticks = ticks_elapsed(t1, t2);
- break;
}
+ break;
case ACPI_STATE_C3:
/*
next reply other threads:[~2012-04-05 13:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-05 13:39 Wei Wang [this message]
2012-04-05 14:02 ` [PATCH] acpi: Fix an incorrect code path in acpi_processor_idle() Jan Beulich
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