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 0FD8E6B0055 for ; Sat, 8 Aug 2009 01:47:09 -0400 (EDT) Received: by gxk3 with SMTP id 3so2559850gxk.14 for ; Fri, 07 Aug 2009 22:47:14 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1249666815-28784-2-git-send-email-mel@csn.ul.ie> References: <1249666815-28784-1-git-send-email-mel@csn.ul.ie> <1249666815-28784-2-git-send-email-mel@csn.ul.ie> Date: Sat, 8 Aug 2009 14:47:13 +0900 Message-ID: <2f11576a0908072247y3d17c977i31ea3bca82058083@mail.gmail.com> Subject: Re: [PATCH 1/6] tracing, page-allocator: Add trace events for page allocation and page freeing From: KOSAKI Motohiro Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Larry Woodman , Ingo Molnar , Andrew Morton , riel@redhat.com, Peter Zijlstra , LKML , linux-mm@kvack.org List-ID: 2009/8/8 Mel Gorman : > This patch adds trace events for the allocation and freeing of pages, > including the freeing of pagevecs. =A0Using the events, it will be known = what > struct page and pfns are being allocated and freed and what the call site > was in many cases. > > The page alloc tracepoints be used as an indicator as to whether the work= load > was heavily dependant on the page allocator or not. You can make a guess = based > on vmstat but you can't get a per-process breakdown. Depending on the cal= l > path, the call_site for page allocation may be __get_free_pages() instead > of a useful callsite. Instead of passing down a return address similar to > slab debugging, the user should enable the stacktrace and seg-addr option= s > to get a proper stack trace. > > The pagevec free tracepoint has a different usecase. It can be used to ge= t > a idea of how many pages are being dumped off the LRU and whether it is > kswapd doing the work or a process doing direct reclaim. > > Signed-off-by: Mel Gorman > Acked-by: Rik van Riel Looks good to me. Reviewed-by: KOSAKI Motohiro -- 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