diff options
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/tlb.h | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 8ce15cf20dbf..e629251cb7a7 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -36,9 +36,12 @@ typedef struct free_pte_ctx { struct mm_struct *mm; unsigned int nr; /* set to ~0U means fast mode */ + unsigned int need_flush;/* Really unmapped some ptes? */ unsigned int fullmm; /* non-zero means full mm flush */ unsigned long freed; struct page * pages[FREE_PTE_NR]; + unsigned long flushes;/* stats: count avoided flushes */ + unsigned long avoided_flushes; } mmu_gather_t; /* Users of the generic TLB shootdown code must declare this storage space. */ @@ -66,6 +69,13 @@ static inline void tlb_flush_mmu(mmu_gather_t *tlb, unsigned long start, unsigne { unsigned long nr; + if (!tlb->need_flush) { + tlb->avoided_flushes++; + return; + } + tlb->need_flush = 0; + tlb->flushes++; + tlb_flush(tlb); nr = tlb->nr; if (!tlb_fast_mode(tlb)) { @@ -103,6 +113,7 @@ static inline void tlb_finish_mmu(mmu_gather_t *tlb, unsigned long start, unsign */ static inline void tlb_remove_page(mmu_gather_t *tlb, struct page *page) { + tlb->need_flush = 1; if (tlb_fast_mode(tlb)) { free_page_and_swap_cache(page); return; @@ -112,5 +123,29 @@ static inline void tlb_remove_page(mmu_gather_t *tlb, struct page *page) tlb_flush_mmu(tlb, 0, 0); } -#endif /* _ASM_GENERIC__TLB_H */ +/** + * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation. + * + * Record the fact that pte's were really umapped in ->need_flush, so we can + * later optimise away the tlb invalidate. This helps when userspace is + * unmapping already-unmapped pages, which happens quite a lot. + */ +#define tlb_remove_tlb_entry(tlb, ptep, address) \ + do { \ + tlb->need_flush = 1; \ + __tlb_remove_tlb_entry(tlb, ptep, address); \ + } while (0) + +#define pte_free_tlb(tlb, ptep) \ + do { \ + tlb->need_flush = 1; \ + __pte_free_tlb(tlb, ptep); \ + } while (0) + +#define pmd_free_tlb(tlb, pmdp) \ + do { \ + tlb->need_flush = 1; \ + __pmd_free_tlb(tlb, pmdp); \ + } while (0) +#endif /* _ASM_GENERIC__TLB_H */ |