From cfc319833b5b359bf3bce99564dbac00af7925ac Mon Sep 17 00:00:00 2001
From: Jan Beulich <jbeulich@novell.com>
Date: Tue, 16 Dec 2008 11:46:58 +0000
Subject: [PATCH] x86, 32-bit: improve lazy TLB handling code
Impact: micro-optimize the 32-bit TLB flush code
Use the faster x86_{read,write}_percpu() accessors here.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/include/asm/mmu_context_32.h | 13 ++++++-------
arch/x86/kernel/tlb_32.c | 11 +++++------
2 files changed, 11 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/mmu_context_32.h b/arch/x86/include/asm/mmu_context_32.h
index 8e10015781fb2..7e98ce1d2c0e5 100644
--- a/arch/x86/include/asm/mmu_context_32.h
+++ b/arch/x86/include/asm/mmu_context_32.h
@@ -4,9 +4,8 @@
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
#ifdef CONFIG_SMP
- unsigned cpu = smp_processor_id();
- if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
- per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
+ if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK)
+ x86_write_percpu(cpu_tlbstate.state, TLBSTATE_LAZY);
#endif
}
@@ -20,8 +19,8 @@ static inline void switch_mm(struct mm_struct *prev,
/* stop flush ipis for the previous mm */
cpu_clear(cpu, prev->cpu_vm_mask);
#ifdef CONFIG_SMP
- per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
- per_cpu(cpu_tlbstate, cpu).active_mm = next;
+ x86_write_percpu(cpu_tlbstate.state, TLBSTATE_OK);
+ x86_write_percpu(cpu_tlbstate.active_mm, next);
#endif
cpu_set(cpu, next->cpu_vm_mask);
@@ -36,8 +35,8 @@ static inline void switch_mm(struct mm_struct *prev,
}
#ifdef CONFIG_SMP
else {
- per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
- BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);
+ x86_write_percpu(cpu_tlbstate.state, TLBSTATE_OK);
+ BUG_ON(x86_read_percpu(cpu_tlbstate.active_mm) != next);
if (!cpu_test_and_set(cpu, next->cpu_vm_mask)) {
/* We were in lazy tlb mode and leave_mm disabled
diff --git a/arch/x86/kernel/tlb_32.c b/arch/x86/kernel/tlb_32.c
index f4049f3513b6b..4290d918b58af 100644
--- a/arch/x86/kernel/tlb_32.c
+++ b/arch/x86/kernel/tlb_32.c
@@ -34,9 +34,8 @@ static DEFINE_SPINLOCK(tlbstate_lock);
*/
void leave_mm(int cpu)
{
- if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
- BUG();
- cpu_clear(cpu, per_cpu(cpu_tlbstate, cpu).active_mm->cpu_vm_mask);
+ BUG_ON(x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK);
+ cpu_clear(cpu, x86_read_percpu(cpu_tlbstate.active_mm)->cpu_vm_mask);
load_cr3(swapper_pg_dir);
}
EXPORT_SYMBOL_GPL(leave_mm);
@@ -104,8 +103,8 @@ void smp_invalidate_interrupt(struct pt_regs *regs)
* BUG();
*/
- if (flush_mm == per_cpu(cpu_tlbstate, cpu).active_mm) {
- if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK) {
+ if (flush_mm == x86_read_percpu(cpu_tlbstate.active_mm)) {
+ if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_OK) {
if (flush_va == TLB_FLUSH_ALL)
local_flush_tlb();
else
@@ -238,7 +237,7 @@ static void do_flush_tlb_all(void *info)
unsigned long cpu = smp_processor_id();
__flush_tlb_all();
- if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_LAZY)
+ if (x86_read_percpu(cpu_tlbstate.state) == TLBSTATE_LAZY)
leave_mm(cpu);
}
--
2.30.2