From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 5ABCA6B004F for ; Thu, 18 Jun 2009 15:39:58 -0400 (EDT) Message-ID: <4A3A9844.8030004@redhat.com> Date: Thu, 18 Jun 2009 15:40:52 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [Patch] mm tracepoints update - use case. References: <20090423092933.F6E9.A69D9226@jp.fujitsu.com> <4A36925D.4090000@redhat.com> <20090616170811.99A6.A69D9226@jp.fujitsu.com> <1245352954.3212.67.camel@dhcp-100-19-198.bos.redhat.com> In-Reply-To: <1245352954.3212.67.camel@dhcp-100-19-198.bos.redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Larry Woodman Cc: KOSAKI Motohiro , Ingo Molnar , =?UTF-8?B?RnLpppjpp7tpYyBXZWlzYmVja2Vy?= , Li Zefan , Pekka Enberg , eduard.munteanu@linux360.ro, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rostedt@goodmis.org List-ID: Larry Woodman wrote: >> - Please don't display mm and/or another kernel raw pointer. >> if we assume non stop system, we can't use kernel-dump. Thus kernel pointer >> logging is not so useful. > > OK, I just dont know how valuable the trace output is with out some raw > data like the mm_struct. I believe that we do want something like the mm_struct in the trace info, so we can figure out which process was allocating pages, etc... >> - Please consider how do this feature works on mem-cgroup. >> (IOW, please don't ignore many "if (scanning_global_lru())") Good point, we want to trace cgroup vs non-cgroup reclaims, too. >> - tracepoint caller shouldn't have any assumption of displaying representation. >> e.g. >> wrong) trace_mm_pagereclaim_pgout(mapping, page->index<> good) trace_mm_pagereclaim_pgout(mapping, page) > > OK. > >> that's general and good callback and/or hook manner. How do we figure those out from the page pointer at the time the tracepoint triggers? I believe that it would be useful to export that info in the trace point, since we cannot expect the userspace trace tool to figure out these things from the struct page address. Or did I overlook something here? -- All rights reversed. -- 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