From 287de5b2cb365b98190b5de8ace1c5a31768a5ae Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Tue, 15 Nov 2011 14:49:02 -0800 Subject: [PATCH] x86/mm: Avoid superflous leave_mm() in the TLB flush path If just one page VA tlb is required to be flushed and current task is in lazy TLB state, doing leave_mm() is superfluous because it flushes the whole TLB. This can reduce some TLB miss. Signed-off-by: Shaohua Li Cc: Linus Torvalds Cc: "H. Peter Anvin" Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar --- arch/x86/mm/tlb.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index d6c0418c3e47..304166557366 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -153,13 +153,13 @@ void smp_invalidate_interrupt(struct pt_regs *regs) */ if (f->flush_mm == percpu_read(cpu_tlbstate.active_mm)) { - if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK) { - if (f->flush_va == TLB_FLUSH_ALL) + if (f->flush_va == TLB_FLUSH_ALL) { + if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK) local_flush_tlb(); else - __flush_tlb_one(f->flush_va); + leave_mm(cpu); } else - leave_mm(cpu); + __flush_tlb_one(f->flush_va); } out: ack_APIC_irq(); @@ -306,12 +306,8 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long va) preempt_disable(); - if (current->active_mm == mm) { - if (current->mm) - __flush_tlb_one(va); - else - leave_mm(smp_processor_id()); - } + if (current->active_mm == mm) + __flush_tlb_one(va); if (cpumask_any_but(mm_cpumask(mm), smp_processor_id()) < nr_cpu_ids) flush_tlb_others(mm_cpumask(mm), mm, va); -- 2.39.5