From b8bcfe997e46150fedcc3f5b26b846400122fdd9 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date: Tue, 17 Feb 2009 23:05:19 -0800
Subject: x86/paravirt: remove lazy mode in interrupts
Impact: simplification, robustness
Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE
when in an interrupt. This prevents interrupt code from
accidentally inheriting an outer lazy state, and instead
does everything synchronously. Outer batched operations
are left deferred.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/paravirt.c | 3 +++
1 file changed, 3 insertions(+)
(limited to 'arch/x86/kernel/paravirt.c')
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 63dd358d8ee1..8ab250ac498b 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -282,6 +282,9 @@ void paravirt_leave_lazy_cpu(void)
enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
{
+ if (in_interrupt())
+ return PARAVIRT_LAZY_NONE;
+
return __get_cpu_var(paravirt_lazy_mode);
}
--
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