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| author |   Nicholas Piggin <npiggin@gmail.com> | 2020-05-04 22:29:07 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-05-28 23:24:34 +1000 |
| commit | 18594f9b8c45484bd527ebc6b08383b95f58ba73 (patch) | |
| tree | f99e1b502708fb802af5b7b494216a68864a435e /arch/powerpc/include | |
| parent | input: i8042 - Remove special PowerPC handling (diff) | |
| download | linux-dev-18594f9b8c45484bd527ebc6b08383b95f58ba73.tar.xz linux-dev-18594f9b8c45484bd527ebc6b08383b95f58ba73.zip | |
powerpc/64s/radix: Don't prefetch DAR in update_mmu_cache
The idea behind this prefetch was to kick off a page table walk before
returning from the fault, getting some pipelining advantage.
But this never showed up any noticable performance advantage, and in
fact with KUAP the prefetches are actually blocked and cause some
kind of micro-architectural fault. Removing this improves page fault
microbenchmark performance by about 9%.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Keep the early return in update_mmu_cache()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200504122907.49304-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index ec17fc343be0..c4b77fa0b9ad 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -1159,8 +1159,11 @@ extern pmd_t mk_pmd(struct page *page, pgprot_t pgprot); extern pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot); extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd); -extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr, - pmd_t *pmd); +static inline void update_mmu_cache_pmd(struct vm_area_struct *vma, + unsigned long addr, pmd_t *pmd) +{ +} + extern int hash__has_transparent_hugepage(void); static inline int has_transparent_hugepage(void) { |