From c86c97ff42cd6c6d1bd29eca4dfabeaf2b7f1020 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Wed, 4 Jun 2014 16:06:43 -0700 Subject: [PATCH] mm: softdirty: clear VM_SOFTDIRTY flag inside clear_refs_write() instead of clear_soft_dirty() clear_refs_write() is called earlier than clear_soft_dirty() and it is more natural to clear VM_SOFTDIRTY (which belongs to VMA entry but not PTEs) that early instead of clearing it a way deeper inside call chain. Signed-off-by: Cyrill Gorcunov Cc: Pavel Emelyanov Cc: Hugh Dickins Cc: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 442177b1119a..2101ce46a5d2 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -737,9 +737,6 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma, ptent = pte_file_clear_soft_dirty(ptent); } - if (vma->vm_flags & VM_SOFTDIRTY) - vma->vm_flags &= ~VM_SOFTDIRTY; - set_pte_at(vma->vm_mm, addr, pte, ptent); #endif } @@ -807,8 +804,9 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, if (type == CLEAR_REFS_SOFT_DIRTY) { soft_dirty_cleared = true; - pr_warn_once("The pagemap bits 55-60 has changed their meaning! " - "See the linux/Documentation/vm/pagemap.txt for details.\n"); + pr_warn_once("The pagemap bits 55-60 has changed their meaning!" + " See the linux/Documentation/vm/pagemap.txt for " + "details.\n"); } task = get_proc_task(file_inode(file)); @@ -839,11 +837,17 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, * * Writing 3 to /proc/pid/clear_refs only affects file * mapped pages. + * + * Writing 4 to /proc/pid/clear_refs affects all pages. */ if (type == CLEAR_REFS_ANON && vma->vm_file) continue; if (type == CLEAR_REFS_MAPPED && !vma->vm_file) continue; + if (type == CLEAR_REFS_SOFT_DIRTY) { + if (vma->vm_flags & VM_SOFTDIRTY) + vma->vm_flags &= ~VM_SOFTDIRTY; + } walk_page_range(vma->vm_start, vma->vm_end, &clear_refs_walk); } -- 2.20.1