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Commit 15aa3682 authored by Mel Gorman's avatar Mel Gorman Committed by Ingo Molnar
Browse files

x86/mm: Clean up inconsistencies when flushing TLB ranges 



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: default avatarMel Gorman <mgorman@suse.de>
Tested-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
Reviewed-by: default avatarAlex Shi <alex.shi@linaro.org>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/n/tip-Iz5gcahrgskIldvukulzi0hh@git.kernel.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ec659934

arch/x86/mm/tlb.c

+6 −6
Original line number Diff line number Diff line
@@ -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_tlb_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_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);