Some MMU notifier need to be able to sleep during callback. This was
broken by c7ab0d2fdc84 ("mm: convert try_to_unmap_one() to use
page_vma_mapped_walk()").This patch restore the sleep ability and properly capture the range of address that needs to be invalidated. Relevent threads: https://lkml.kernel.org/r/[email protected] https://lkml.kernel.org/r/[email protected] https://marc.info/?l=kvm&m=150327081325160&w=2 Signed-off-by: Jérôme Glisse <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Bernhard Held <[email protected]> Cc: Adam Borowski <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Wanpeng Li <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Takashi Iwai <[email protected]> Cc: Nadav Amit <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Cc: axie <[email protected]> Cc: Andrew Morton <[email protected]> --- mm/rmap.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index c8993c63eb25..0b25b720f494 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -888,6 +888,8 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma, .flags = PVMW_SYNC, }; int *cleaned = arg; + bool invalidate = false; + unsigned long start = address, end = address; while (page_vma_mapped_walk(&pvmw)) { int ret = 0; @@ -905,6 +907,9 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma, entry = pte_mkclean(entry); set_pte_at(vma->vm_mm, address, pte, entry); ret = 1; + invalidate = true; + /* range is exclusive */ + end = pvmw.address + PAGE_SIZE; } else { #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE pmd_t *pmd = pvmw.pmd; @@ -919,18 +924,22 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma, entry = pmd_mkclean(entry); set_pmd_at(vma->vm_mm, address, pmd, entry); ret = 1; + invalidate = true; + /* range is exclusive */ + end = pvmw.address + PAGE_SIZE; #else /* unexpected pmd-mapped page? */ WARN_ON_ONCE(1); #endif } - if (ret) { - mmu_notifier_invalidate_page(vma->vm_mm, address); + if (ret) (*cleaned)++; - } } + if (invalidate) + mmu_notifier_invalidate_range(vma->vm_mm, start, end); + return true; } @@ -1323,8 +1332,9 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, }; pte_t pteval; struct page *subpage; - bool ret = true; + bool ret = true, invalidate = false; enum ttu_flags flags = (enum ttu_flags)arg; + unsigned long start = address, end = address; /* munlock has nothing to gain from examining un-locked vmas */ if ((flags & TTU_MUNLOCK) && !(vma->vm_flags & VM_LOCKED)) @@ -1490,8 +1500,14 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, discard: page_remove_rmap(subpage, PageHuge(page)); put_page(page); - mmu_notifier_invalidate_page(mm, address); + invalidate = true; + /* range is exclusive */ + end = address + PAGE_SIZE; } + + if (invalidate) + mmu_notifier_invalidate_range(mm, start, end); + return ret; } -- 2.13.5
