> On Mon, Dec 20, 2010 at 11:21 AM, KOSAKI Motohiro > <kosaki.motohiro@xxxxxxxxxxxxxx> wrote: > >> This patch series changes remove_from_page_cache's page ref counting > >> rule. page cache ref count is decreased in remove_from_page_cache. > >> So we don't need call again in caller context. > >> > >> Cc: Nick Piggin <npiggin@xxxxxxx> > >> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > >> Cc: linux-mm@xxxxxxxxx > >> Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx> > >> --- > >> mm/truncate.c | 1 - > >> 1 files changed, 0 insertions(+), 1 deletions(-) > >> > >> diff --git a/mm/truncate.c b/mm/truncate.c > >> index 9ee5673..8decb93 100644 > >> --- a/mm/truncate.c > >> +++ b/mm/truncate.c > >> @@ -114,7 +114,6 @@ truncate_complete_page(struct address_space *mapping, struct page *page) > >> * calls cleancache_put_page (and note page->mapping is now NULL) > >> */ > >> cleancache_flush_page(mapping, page); > >> - page_cache_release(page); /* pagecache ref */ > >> return 0; > > > > Do we _always_ have stable page reference here? IOW, I can assume > > I think so. > Because the page is locked so caller have to hold a ref to unlock it. Hmm... Perhaps, I'm missing something. But I think __memory_failure() only lock compaund_head page. not all. example. > > > cleancache_flush_page() doesn't cause NULL deref? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href