From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346Ab0FACgJ (ORCPT ); Mon, 31 May 2010 22:36:09 -0400 Received: from mga03.intel.com ([143.182.124.21]:56806 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752739Ab0FACgH (ORCPT ); Mon, 31 May 2010 22:36:07 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.53,337,1272870000"; d="scan'208";a="283400949" Subject: Re: [rfc] Describe events in a structured way via sysfs From: Lin Ming To: Ingo Molnar Cc: Peter Zijlstra , Greg KH , Lin Ming , Corey Ashford , Frederic Weisbecker , Paul Mundt , "eranian@gmail.com" , "Gary.Mohr@Bull.com" , "arjan@linux.intel.com" , "Zhang, Yanmin" , Paul Mackerras , "David S. Miller" , Russell King , Arnaldo Carvalho de Melo , Will Deacon , Maynard Johnson , Carl Love , Kay Sievers , lkml , Thomas Gleixner In-Reply-To: References: <1274233602.3036.84.camel@localhost> <20100518200524.GA20223@kroah.com> <1274236496.3603.22.camel@minggr.sh.intel.com> <20100519024823.GA25229@kroah.com> <1274253276.5605.10124.camel@twins> <20100520184213.GB21030@kroah.com> <20100520201418.GB11470@elte.hu> <20100520231229.GB8335@kroah.com> <1274429038.1674.1684.camel@laptop> <20100521094053.GA4658@elte.hu> Content-Type: text/plain Date: Tue, 01 Jun 2010 10:34:32 +0800 Message-Id: <1275359672.7586.85.camel@minggr.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > * Peter Zijlstra wrote: > > > On Thu, 2010-05-20 at 16:12 -0700, Greg KH wrote: > > > > How deep in the device tree are you really going to be > > > caring about? It sounds like the large majority of > > > events are only going to be coming from the "system" > > > type objects (cpu, nodes, memory, etc.) and very few > > > would be from things that we consider a 'struct > > > device' today (like a pci, usb, scsi, or input, etc.) > > > > The general noise I hear from the hardware people is > > that we'll see more and more device-level stuff - bus > > bridges/controller and actual devices (GPUs, NICs etc.) > > will be wanting to export performance metrics. > > There's (much) more: > > - laptops want to provide power level/usage metrics, > > - we could express a lot of special, lower level > (transport specific) disk IO stats via events as well - > without having to push those stats to a higher level > (where it might not make sense). Currently such kinds > of stats/metrics are very device/subsystem specific > way, if they are provided at all. > > Also, we already have quite a few per device tracepoints > upstream. Here are a few examples: > > - GPU tracepoints (trace_i915_gem_request_submit(), etc.) > - WIFI tracepoints (trace_iwlwifi_dev_ioread32(), etc.) > - block tracepoints (trace_block_bio_complete()) > > So these would be attached to: > > # GEM events of drm/card0: > /sys/devices/pci0000:00/0000:00:02.0/drm/card0/events/i915_gem_request_submit/ > > # Wifi-ioread events of wlan0: > /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ioread32/ > > # whole sdb disk events: > /sys/block/sdb/events/block_bio_complete/ > > # sdb1 partition events: > /sys/block/sdb/sdb1/events/block_bio_complete/ > The difficulty is how to know where each event should be attached to. struct ftrace_event_call *call; for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { /* where will this event be attached to? */ } Any idea? Thanks, Lin Ming