From b478458aeebfc55fe409abec43794ac72a623c79 Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@novell.com>
Date: Mon, 12 May 2008 15:44:39 +0200
Subject: [PATCH] x86: avoid re-loading LDT in unrelated address spaces
Performance optimization.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/ldt.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c
index 0224c3637c73..21f2bae98c15 100644
--- a/arch/x86/kernel/ldt.c
+++ b/arch/x86/kernel/ldt.c
@@ -20,9 +20,9 @@
#include <asm/mmu_context.h>
#ifdef CONFIG_SMP
-static void flush_ldt(void *null)
+static void flush_ldt(void *current_mm)
{
- if (current->active_mm)
+ if (current->active_mm == current_mm)
load_LDT(¤t->active_mm->context);
}
#endif
@@ -68,7 +68,7 @@ static int alloc_ldt(mm_context_t *pc, int mincount, int reload)
load_LDT(pc);
mask = cpumask_of_cpu(smp_processor_id());
if (!cpus_equal(current->mm->cpu_vm_mask, mask))
- smp_call_function(flush_ldt, NULL, 1, 1);
+ smp_call_function(flush_ldt, current->mm, 1, 1);
preempt_enable();
#else
load_LDT(pc);
--
2.34.1