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| author | Jérôme Glisse <jglisse@redhat.com> | 2017-11-15 17:34:11 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:03 -0800 |
| commit | 4645b9fe84bf4878f04c7959a75df7c3c2d1bbb9 (patch) | |
| tree | 83fc19e23f907ea229fd8a99aedbbf967057eae4 /include/linux/mmu_notifier.h | |
| parent | 0f10851ea475e08896ee5d9a2036d1bb46a8f3a4 (diff) | |
| download | lwn-4645b9fe84bf4878f04c7959a75df7c3c2d1bbb9.tar.gz lwn-4645b9fe84bf4878f04c7959a75df7c3c2d1bbb9.zip | |
mm/mmu_notifier: avoid call to invalidate_range() in range_end()
This is an optimization patch that only affect mmu_notifier users which
rely on the invalidate_range() callback. This patch avoids calling that
callback twice in a row from inside __mmu_notifier_invalidate_range_end
Existing pattern (before this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_end()
mmu_notifier_invalidate_range()
New pattern (after this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_only_end()
We call the invalidate_range callback after clearing the page table
under the page table lock and we skip the call to invalidate_range
inside the __mmu_notifier_invalidate_range_end() function.
Idea from Andrea Arcangeli
Link: http://lkml.kernel.org/r/20171017031003.7481-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmu_notifier.h')
| -rw-r--r-- | include/linux/mmu_notifier.h | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 130831718e95..b25dc9db19fc 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -214,7 +214,8 @@ extern void __mmu_notifier_change_pte(struct mm_struct *mm, extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end); extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, - unsigned long start, unsigned long end); + unsigned long start, unsigned long end, + bool only_end); extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end); @@ -268,7 +269,14 @@ static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm, unsigned long start, unsigned long end) { if (mm_has_notifiers(mm)) - __mmu_notifier_invalidate_range_end(mm, start, end); + __mmu_notifier_invalidate_range_end(mm, start, end, false); +} + +static inline void mmu_notifier_invalidate_range_only_end(struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + if (mm_has_notifiers(mm)) + __mmu_notifier_invalidate_range_end(mm, start, end, true); } static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, @@ -439,6 +447,11 @@ static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm, { } +static inline void mmu_notifier_invalidate_range_only_end(struct mm_struct *mm, + unsigned long start, unsigned long end) +{ +} + static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, unsigned long start, unsigned long end) { |