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Subject[PATCH 1/3] x86: mm: Clean up inconsistencies when flushing TLB ranges
Date
NR_TLB_LOCAL_FLUSH_ALL is not always accounted for correctly and the
comparison with total_vm is done before taking tlb_flushall_shift into
account. Clean it up.

Signed-off-by: Mel Gorman <mgorman@suse.de>
---
arch/x86/mm/tlb.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index ae699b3..09b8cb8 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -189,6 +189,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
{
unsigned long addr;
unsigned act_entries, tlb_entries = 0;
+ unsigned long nr_base_pages;

preempt_disable();
if (current->active_mm != mm)
@@ -210,18 +211,17 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
tlb_entries = tlb_lli_4k[ENTRIES];
else
tlb_entries = tlb_lld_4k[ENTRIES];
+
/* Assume all of TLB entries was occupied by this task */
- act_entries = mm->total_vm > tlb_entries ? tlb_entries : mm->total_vm;
+ act_entries = tlb_entries >> tlb_flushall_shift;
+ act_entries = mm->total_vm > act_entries ? act_entries : mm->total_vm;
+ nr_base_pages = (end - start) >> PAGE_SHIFT;

/* tlb_flushall_shift is on balance point, details in commit log */
- if ((end - start) >> PAGE_SHIFT > act_entries >> tlb_flushall_shift) {
+ if (nr_base_pages > act_entries || has_large_page(mm, start, end)) {
count_vm_event(NR_TLB_LOCAL_FLUSH_ALL);
local_flush_tlb();
} else {
- if (has_large_page(mm, start, end)) {
- local_flush_tlb();
- goto flush_all;
- }
/* flush range by one by one 'invlpg' */
for (addr = start; addr < end; addr += PAGE_SIZE) {
count_vm_event(NR_TLB_LOCAL_FLUSH_ONE);
--
1.8.4


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