From 5c64f52acdbc615e3ef58692f42ee00b83d0225d Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Wed, 11 Feb 2015 15:27:46 -0800 Subject: clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk() clear_refs_write() has some prechecks to determine if we really walk over a given vma. Now we have a test_walk() callback to filter vmas, so let's utilize it. Signed-off-by: Naoya Horiguchi Acked-by: Kirill A. Shutemov Cc: "Kirill A. Shutemov" Cc: Andrea Arcangeli Cc: Cyrill Gorcunov Cc: Dave Hansen Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 46 ++++++++++++++++++++++------------------------ 1 file changed, 22 insertions(+), 24 deletions(-) (limited to 'fs/proc/task_mmu.c') diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 73425398b38c..bed0834715a5 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -736,7 +736,6 @@ enum clear_refs_types { }; struct clear_refs_private { - struct vm_area_struct *vma; enum clear_refs_types type; }; @@ -767,7 +766,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct mm_walk *walk) { struct clear_refs_private *cp = walk->private; - struct vm_area_struct *vma = cp->vma; + struct vm_area_struct *vma = walk->vma; pte_t *pte, ptent; spinlock_t *ptl; struct page *page; @@ -801,6 +800,25 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, return 0; } +static int clear_refs_test_walk(unsigned long start, unsigned long end, + struct mm_walk *walk) +{ + struct clear_refs_private *cp = walk->private; + struct vm_area_struct *vma = walk->vma; + + /* + * Writing 1 to /proc/pid/clear_refs affects all pages. + * Writing 2 to /proc/pid/clear_refs only affects anonymous pages. + * Writing 3 to /proc/pid/clear_refs only affects file mapped pages. + * Writing 4 to /proc/pid/clear_refs affects all pages. + */ + if (cp->type == CLEAR_REFS_ANON && vma->vm_file) + return 1; + if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file) + return 1; + return 0; +} + static ssize_t clear_refs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -841,6 +859,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, }; struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range, + .test_walk = clear_refs_test_walk, .mm = mm, .private = &cp, }; @@ -860,28 +879,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, } mmu_notifier_invalidate_range_start(mm, 0, -1); } - for (vma = mm->mmap; vma; vma = vma->vm_next) { - cp.vma = vma; - if (is_vm_hugetlb_page(vma)) - continue; - /* - * Writing 1 to /proc/pid/clear_refs affects all pages. - * - * Writing 2 to /proc/pid/clear_refs only affects - * Anonymous pages. - * - * 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; - walk_page_range(vma->vm_start, vma->vm_end, - &clear_refs_walk); - } + walk_page_range(0, ~0UL, &clear_refs_walk); if (type == CLEAR_REFS_SOFT_DIRTY) mmu_notifier_invalidate_range_end(mm, 0, -1); flush_tlb_mm(mm); -- cgit v1.2.3-55-g7522