From 0761bca00771c11254d82acd02d8111a8f4d98da Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 2 Dec 2011 14:13:08 +1100 Subject: [PATCH] thp: add tlb_remove_pmd_tlb_entry We have tlb_remove_tlb_entry to indicate a pte tlb flush entry should be flushed, but not a corresponding API for pmd entry. This isn't a problem so far because THP is only for x86 currently and tlb_flush() under x86 will flush entire TLB. But this is confusion and could be missed if thp is ported to other arch. Also convert tlb->need_flush = 1 to a VM_BUG_ON(!tlb->need_flush) in __tlb_remove_page() as suggested by Andrea Arcangeli. __tlb_remove_page() is supposed to be called after tlb_remove_xxx_tlb_entry() and we can catch any misuse. Signed-off-by: Shaohua Li Reviewed-by: Andrea Arcangeli Cc: David Rientjes Cc: Johannes Weiner Cc: Minchan Kim Signed-off-by: Andrew Morton --- include/asm-generic/tlb.h | 14 ++++++++++++++ include/linux/huge_mm.h | 2 +- mm/huge_memory.c | 3 ++- mm/memory.c | 4 ++-- 4 files changed, 19 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index e58fa777fa09..f96a5b58a975 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -139,6 +139,20 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) __tlb_remove_tlb_entry(tlb, ptep, address); \ } while (0) +/** + * tlb_remove_pmd_tlb_entry - remember a pmd mapping for later tlb invalidation + * This is a nop so far, because only x86 needs it. + */ +#ifndef __tlb_remove_pmd_tlb_entry +#define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0) +#endif + +#define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \ + do { \ + tlb->need_flush = 1; \ + __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \ + } while (0) + #define pte_free_tlb(tlb, ptep, address) \ do { \ tlb->need_flush = 1; \ diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 33e47d8aeddb..7246cfa602d0 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -18,7 +18,7 @@ extern struct page *follow_trans_huge_pmd(struct mm_struct *mm, unsigned int flags); extern int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, - pmd_t *pmd); + pmd_t *pmd, unsigned long addr); extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, unsigned char *vec); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 964fc5a2edd2..5a595554bd8c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1026,7 +1026,7 @@ out: } int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, - pmd_t *pmd) + pmd_t *pmd, unsigned long addr) { int ret = 0; @@ -1042,6 +1042,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, pgtable = get_pmd_huge_pte(tlb->mm); page = pmd_page(*pmd); pmd_clear(pmd); + tlb_remove_pmd_tlb_entry(tlb, pmd, addr); page_remove_rmap(page); VM_BUG_ON(page_mapcount(page) < 0); add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); diff --git a/mm/memory.c b/mm/memory.c index ad784bf57d07..30f35e9ea34b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -293,7 +293,7 @@ int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) { struct mmu_gather_batch *batch; - tlb->need_flush = 1; + VM_BUG_ON(!tlb->need_flush); if (tlb_fast_mode(tlb)) { free_page_and_swap_cache(page); @@ -1231,7 +1231,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, if (next-addr != HPAGE_PMD_SIZE) { VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem)); split_huge_page_pmd(vma->vm_mm, pmd); - } else if (zap_huge_pmd(tlb, vma, pmd)) + } else if (zap_huge_pmd(tlb, vma, pmd, addr)) continue; /* fall through */ } -- 2.39.5