From: Avi Kivity <avi@redhat.com>
To: "Ingo Molnar" <mingo@elte.hu>, "H. Peter Anvin" <hpa@zytor.com>,
"Török Edwin" <edwintorok@gmail.com>
Cc: kvm@vger.kernel.org, Christoph Lameter <cl@linux.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH] x86: fix mwait_play_dead() faulting on mwait-incapable cpus
Date: Mon, 30 May 2011 08:23:57 -0400 [thread overview]
Message-ID: <1306758237-9327-1-git-send-email-avi@redhat.com> (raw)
In-Reply-To: <201105301143.p4UBhco4001230@demeter2.kernel.org>
A logic error in mwait_play_dead() causes the kernel to use mwait
even on cpus which don't support it, such as KVM virtual cpus.
Introduced by 349c004e3d31fd.
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=36222
Reported-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kernel/smpboot.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index eefd967..33a0c11 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1332,7 +1332,7 @@ static inline void mwait_play_dead(void)
void *mwait_ptr;
struct cpuinfo_x86 *c = __this_cpu_ptr(&cpu_info);
- if (!this_cpu_has(X86_FEATURE_MWAIT) && mwait_usable(c))
+ if (!(this_cpu_has(X86_FEATURE_MWAIT) && mwait_usable(c)))
return;
if (!this_cpu_has(X86_FEATURE_CLFLSH))
return;
--
1.7.5.3
next parent reply other threads:[~2011-05-30 12:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <201105301143.p4UBhco4001230@demeter2.kernel.org>
2011-05-30 12:23 ` Avi Kivity [this message]
2011-05-30 12:36 ` [PATCH] x86: fix mwait_play_dead() faulting on mwait-incapable cpus Török Edwin
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