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| author | Peter Zijlstra <peterz@infradead.org> | 2007-10-08 18:54:37 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-08 12:58:14 -0700 |
| commit | a200ee182a016752464a12cb2e8762e48254bb09 (patch) | |
| tree | 7b273f002625a4c368f7b20b144990f7f4f81df9 /mm/memory.c | |
| parent | 3eb215de26e6e94bf5fed9cb77230c383b30e53b (diff) | |
| download | lwn-a200ee182a016752464a12cb2e8762e48254bb09.tar.gz lwn-a200ee182a016752464a12cb2e8762e48254bb09.zip | |
mm: set_page_dirty_balance() vs ->page_mkwrite()
All the current page_mkwrite() implementations also set the page dirty. Which
results in the set_page_dirty_balance() call to _not_ call balance, because the
page is already found dirty.
This allows us to dirty a _lot_ of pages without ever hitting
balance_dirty_pages(). Not good (tm).
Force a balance call if ->page_mkwrite() was successful.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index c0e7741a98de..f82b359b2745 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1639,6 +1639,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, struct page *old_page, *new_page; pte_t entry; int reuse = 0, ret = 0; + int page_mkwrite = 0; struct page *dirty_page = NULL; old_page = vm_normal_page(vma, address, orig_pte); @@ -1687,6 +1688,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, page_cache_release(old_page); if (!pte_same(*page_table, orig_pte)) goto unlock; + + page_mkwrite = 1; } dirty_page = old_page; get_page(dirty_page); @@ -1774,7 +1777,7 @@ unlock: * do_no_page is protected similarly. */ wait_on_page_locked(dirty_page); - set_page_dirty_balance(dirty_page); + set_page_dirty_balance(dirty_page, page_mkwrite); put_page(dirty_page); } return ret; @@ -2322,6 +2325,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, struct page *dirty_page = NULL; struct vm_fault vmf; int ret; + int page_mkwrite = 0; vmf.virtual_address = (void __user *)(address & PAGE_MASK); vmf.pgoff = pgoff; @@ -2398,6 +2402,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, anon = 1; /* no anon but release vmf.page */ goto out; } + page_mkwrite = 1; } } @@ -2453,7 +2458,7 @@ out_unlocked: if (anon) page_cache_release(vmf.page); else if (dirty_page) { - set_page_dirty_balance(dirty_page); + set_page_dirty_balance(dirty_page, page_mkwrite); put_page(dirty_page); } |