The patch titled
Subject: x86: tlb flush avoid superflous leave_mm()
has been added to the -mm tree. Its filename is
x86-tlb-flush-avoid-superflous-leave_mm.patch
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------------------------------------------------------
From: Shaohua Li <shaohua.li@xxxxxxxxx>
Subject: x86: tlb flush avoid superflous leave_mm()
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 <shaohua.li@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxx>
---
arch/x86/mm/tlb.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff -puN arch/x86/mm/tlb.c~x86-tlb-flush-avoid-superflous-leave_mm arch/x86/mm/tlb.c
--- a/arch/x86/mm/tlb.c~x86-tlb-flush-avoid-superflous-leave_mm
+++ a/arch/x86/mm/tlb.c
@@ -155,13 +155,13 @@ void smp_invalidate_interrupt(struct pt_
*/
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();
@@ -309,12 +309,8 @@ void flush_tlb_page(struct vm_area_struc
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);
_
Subject: Subject: x86: tlb flush avoid superflous leave_mm()
Patches currently in -mm which might be from shaohua.li@xxxxxxxxx are
origin.patch
linux-next.patch
x86-tlb-flush-avoid-superflous-leave_mm.patch
vmscan-add-block-plug-for-page-reclaim.patch
vmscan-count-pages-into-balanced-for-zone-with-good-watermark.patch
vmscan-promote-shared-file-mapped-pages.patch
vmscan-activate-executable-pages-after-first-usage.patch
intel_idle-fix-api-misuse.patch
intel_idle-disable-auto_demotion-for-hotplugged-cpus.patch
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