From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 3EF6C9000C1 for ; Tue, 26 Apr 2011 05:20:33 -0400 (EDT) Date: Tue, 26 Apr 2011 17:20:29 +0800 From: Wu Fengguang Subject: Re: readahead and oom Message-ID: <20110426092029.GA27053@localhost> References: <20110426055521.GA18473@localhost> <20110426062535.GB19717@localhost> <20110426063421.GC19717@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Dave Young , linux-mm , Linux Kernel Mailing List , Andrew Morton , Mel Gorman Minchan, > > +static inline struct page *page_cache_alloc_cold_noretry(struct address_space *x) > > +{ > > + A A A return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD|__GFP_NORETRY); > > It makes sense to me but it could make a noise about page allocation > failure. I think it's not desirable. > How about adding __GFP_NOWARAN? Yeah it makes sense. Here is the new version. Thanks, Fengguang --- Subject: readahead: readahead page allocations is OK to fail Date: Tue Apr 26 14:29:40 CST 2011 Pass __GFP_NORETRY|__GFP_NOWARN for readahead page allocations. readahead page allocations are completely optional. They are OK to fail and in particular shall not trigger OOM on themselves. Reported-by: Dave Young Reviewed-by: KOSAKI Motohiro Signed-off-by: Wu Fengguang --- include/linux/pagemap.h | 6 ++++++ mm/readahead.c | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) --- linux-next.orig/include/linux/pagemap.h 2011-04-26 14:27:46.000000000 +0800 +++ linux-next/include/linux/pagemap.h 2011-04-26 17:17:13.000000000 +0800 @@ -219,6 +219,12 @@ static inline struct page *page_cache_al return __page_cache_alloc(mapping_gfp_mask(x)|__GFP_COLD); } +static inline struct page *page_cache_alloc_readahead(struct address_space *x) +{ + return __page_cache_alloc(mapping_gfp_mask(x) | + __GFP_COLD | __GFP_NORETRY | __GFP_NOWARN); +} + typedef int filler_t(void *, struct page *); extern struct page * find_get_page(struct address_space *mapping, --- linux-next.orig/mm/readahead.c 2011-04-26 14:27:02.000000000 +0800 +++ linux-next/mm/readahead.c 2011-04-26 17:17:25.000000000 +0800 @@ -180,7 +180,7 @@ __do_page_cache_readahead(struct address if (page) continue; - page = page_cache_alloc_cold(mapping); + page = page_cache_alloc_readahead(mapping); if (!page) break; page->index = page_offset; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org