From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 84EEF6B0047 for ; Tue, 28 Apr 2009 06:04:20 -0400 (EDT) Received: by fxm22 with SMTP id 22so564700fxm.38 for ; Tue, 28 Apr 2009 03:04:22 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20090428093621.GD21085@elte.hu> References: <20090428010907.912554629@intel.com> <20090428014920.769723618@intel.com> <20090428065507.GA2024@elte.hu> <20090428074031.GK27382@one.firstfloor.org> <1240909484.1982.16.camel@penberg-laptop> <20090428091508.GA21085@elte.hu> <84144f020904280219p197d5ceag846ae9a80a76884e@mail.gmail.com> <84144f020904280225h490ef682p8973cb1241a1f3ea@mail.gmail.com> <20090428093621.GD21085@elte.hu> Date: Tue, 28 Apr 2009 12:57:16 +0300 Message-ID: <84144f020904280257j57b5b686k91cc4096a8e5ca29@mail.gmail.com> Subject: Re: [PATCH 5/5] proc: export more page flags in /proc/kpageflags From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Ingo Molnar Cc: Andi Kleen , Wu Fengguang , Steven Rostedt , =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= , Larry Woodman , Peter Zijlstra , Eduard - Gabriel Munteanu , Andrew Morton , LKML , KOSAKI Motohiro , Matt Mackall , Alexey Dobriyan , "linux-mm@kvack.org" List-ID: Hi Ingo, On Tue, Apr 28, 2009 at 12:36 PM, Ingo Molnar wrote: > I 'integrate' traces all the time to get summary counts. This series > of dynamic events: > > =A0allocation > =A0page count up > =A0page count up > =A0page count down > =A0page count up > =A0page count up > =A0page count up > =A0page count up > > integrates into: "page count is 6". > > Note that "integration" can be done wholly in the kernel too, > without going to the overhead of streaming all dynamic events to > user-space, just to summarize data into counts, in-kernel. That is > what the ftrace statistics framework and various ftrace plugins are > about. > > Also, it might make sense to extend the framework with a series of > 'get current object state' events when tracing is turned on. A > special case of _that_ would in essence be what the /proc hack does > now - just expressed in a much more generic, and a much more usable > form. I guess the main question here is whether this approach will scale to something like kmalloc() or the page allocator in production environments. For any serious workload, the frequency of events is going to be pretty high. Pekka -- 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