From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx173.postini.com [74.125.245.173]) by kanga.kvack.org (Postfix) with SMTP id 9A3C06B0032 for ; Mon, 19 Aug 2013 11:22:00 -0400 (EDT) Date: Mon, 19 Aug 2013 16:07:45 +0100 From: Mel Gorman Subject: Re: [PATCH v2 6/7] mm: munlock: remove redundant get_page/put_page pair on the fast path Message-ID: <20130819150745.GF23002@suse.de> References: <1376915022-12741-1-git-send-email-vbabka@suse.cz> <1376915022-12741-7-git-send-email-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1376915022-12741-7-git-send-email-vbabka@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Andrew Morton , J?rn Engel , Michel Lespinasse , Hugh Dickins , Rik van Riel , Johannes Weiner , Michal Hocko , linux-mm@kvack.org On Mon, Aug 19, 2013 at 02:23:41PM +0200, Vlastimil Babka wrote: > The performance of the fast path in munlock_vma_range() can be further improved > by avoiding atomic ops of a redundant get_page()/put_page() pair. > > When calling get_page() during page isolation, we already have the pin from > follow_page_mask(). This pin will be then returned by __pagevec_lru_add(), > after which we do not reference the pages anymore. > > After this patch, an 8% speedup was measured for munlocking a 56GB large memory > area with THP disabled. > > Signed-off-by: Vlastimil Babka > Reviewed-by: Jorn Engel Acked-by: Mel Gorman -- Mel Gorman SUSE Labs -- 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/ . Don't email: email@kvack.org