From 0c942a4539c09adf09097315cc174aefd0eeedf7 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Sat, 29 Oct 2005 18:15:53 -0700 Subject: [PATCH] [PATCH] mm: msync_pte_range progress Use latency breaking in msync_pte_range like that in copy_pte_range, instead of the ugly CONFIG_PREEMPT filemap_msync alternatives. Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/msync.c | 38 ++++++++++++++------------------------ 1 file changed, 14 insertions(+), 24 deletions(-) diff --git a/mm/msync.c b/mm/msync.c index 9cab3f2d586..3b5f1c521d4 100644 --- a/mm/msync.c +++ b/mm/msync.c @@ -26,12 +26,21 @@ static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end) { pte_t *pte; + int progress = 0; +again: pte = pte_offset_map(pmd, addr); do { unsigned long pfn; struct page *page; + if (progress >= 64) { + progress = 0; + if (need_resched() || + need_lockbreak(&vma->vm_mm->page_table_lock)) + break; + } + progress++; if (!pte_present(*pte)) continue; if (!pte_maybe_dirty(*pte)) @@ -46,8 +55,12 @@ static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (ptep_clear_flush_dirty(vma, addr, pte) || page_test_and_clear_dirty(page)) set_page_dirty(page); + progress += 3; } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap(pte - 1); + cond_resched_lock(&vma->vm_mm->page_table_lock); + if (addr != end) + goto again; } static inline void msync_pmd_range(struct vm_area_struct *vma, pud_t *pud, @@ -106,29 +119,6 @@ static void msync_page_range(struct vm_area_struct *vma, spin_unlock(&mm->page_table_lock); } -#ifdef CONFIG_PREEMPT -static inline void filemap_msync(struct vm_area_struct *vma, - unsigned long addr, unsigned long end) -{ - const size_t chunk = 64 * 1024; /* bytes */ - unsigned long next; - - do { - next = addr + chunk; - if (next > end || next < addr) - next = end; - msync_page_range(vma, addr, next); - cond_resched(); - } while (addr = next, addr != end); -} -#else -static inline void filemap_msync(struct vm_area_struct *vma, - unsigned long addr, unsigned long end) -{ - msync_page_range(vma, addr, end); -} -#endif - /* * MS_SYNC syncs the entire file - including mappings. * @@ -150,7 +140,7 @@ static int msync_interval(struct vm_area_struct *vma, return -EBUSY; if (file && (vma->vm_flags & VM_SHARED)) { - filemap_msync(vma, addr, end); + msync_page_range(vma, addr, end); if (flags & MS_SYNC) { struct address_space *mapping = file->f_mapping; -- 2.20.1