From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
If we take the
if (end == TLB_FLUSH_ALL || vmflag & VM_HUGETLB) {
local_flush_tlb();
goto out;
}
path out of flush_tlb_mm_range(), we will have flushed the tlb,
but not incremented NR_TLB_LOCAL_FLUSH_ALL. This unifies the
way out of the function so that we always take a single path when
doing a full tlb flush.
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---
b/arch/x86/mm/tlb.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff -puN arch/x86/mm/tlb.c~fix-missed-global-flush-stat arch/x86/mm/tlb.c
--- a/arch/x86/mm/tlb.c~fix-missed-global-flush-stat 2014-04-21 11:10:35.176852256 -0700
+++ b/arch/x86/mm/tlb.c 2014-04-21 11:10:35.190852888 -0700
@@ -172,8 +172,9 @@ unsigned long tlb_single_page_flush_ceil
void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end, unsigned long vmflag)
{
- int need_flush_others_all = 1;
unsigned long addr;
+ /* do a global flush by default */
+ unsigned long base_pages_to_flush = TLB_FLUSH_ALL;
preempt_disable();
if (current->active_mm != mm)
@@ -184,16 +185,14 @@ void flush_tlb_mm_range(struct mm_struct
goto out;
}
- if (end == TLB_FLUSH_ALL || vmflag & VM_HUGETLB) {
- local_flush_tlb();
- goto out;
- }
+ if ((end != TLB_FLUSH_ALL) && !(vmflag & VM_HUGETLB))
+ base_pages_to_flush = (end - start) >> PAGE_SHIFT;
- if ((end - start) > tlb_single_page_flush_ceiling * PAGE_SIZE) {
+ if (base_pages_to_flush > tlb_single_page_flush_ceiling) {
+ base_pages_to_flush = TLB_FLUSH_ALL;
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
} else {
- need_flush_others_all = 0;
/* flush range by one by one 'invlpg' */
for (addr = start; addr < end; addr += PAGE_SIZE) {
count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
@@ -201,7 +200,7 @@ void flush_tlb_mm_range(struct mm_struct
}
}
out:
- if (need_flush_others_all) {
+ if (base_pages_to_flush == TLB_FLUSH_ALL) {
start = 0UL;
end = TLB_FLUSH_ALL;
}
_
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