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authorShaohua Li <shaohua.li@intel.com>2012-01-12 17:19:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-12 20:13:08 -0800
commitf21760b15dcd091e5afd38d0b97197b45f7ef2ea (patch)
tree84dd0f9016b46630d6b67e48ff0382b78a1bc519
parente5591307f0c1eb733d280a0b72473e01d7f88530 (diff)
downloadop-kernel-dev-f21760b15dcd091e5afd38d0b97197b45f7ef2ea.zip
op-kernel-dev-f21760b15dcd091e5afd38d0b97197b45f7ef2ea.tar.gz
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. The __tlb_remove_page() function is supposed to be called after tlb_remove_xxx_tlb_entry() and we can catch any misuse. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/asm-generic/tlb.h14
-rw-r--r--include/linux/huge_mm.h2
-rw-r--r--mm/huge_memory.c3
-rw-r--r--mm/memory.c4
4 files changed, 19 insertions, 4 deletions
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index e58fa77..f96a5b5 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 a9ace9c..1b92129 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 964fc5a..5a59555 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 829d437..5e30583 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 */
}
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