Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756222AbZAGHn6 (ORCPT ); Wed, 7 Jan 2009 02:43:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754155AbZAGHnV (ORCPT ); Wed, 7 Jan 2009 02:43:21 -0500 Received: from mga12.intel.com ([143.182.124.36]:6106 "EHLO azsmga102.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752326AbZAGHnQ (ORCPT ); Wed, 7 Jan 2009 02:43:16 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.37,225,1231142400"; d="scan'208";a="97224771" Subject: Re: [patch] Performance Counters for Linux, v2 From: "Zhang, Yanmin" To: Ingo Molnar Cc: Arjan van de Ven , linux-kernel@vger.kernel.org, Thomas Gleixner , linux-arch@vger.kernel.org, Andrew Morton , Stephane Eranian , Eric Dumazet , Robert Richter , Peter Anvin , Peter Zijlstra , Steven Rostedt , David Miller , Paul Mackerras In-Reply-To: <20081208114921.GA8635@elte.hu> References: <20081208012211.GA23106@elte.hu> <20081207174932.09673cae@infradead.org> <20081208114921.GA8635@elte.hu> Content-Type: text/plain Date: Wed, 07 Jan 2009 15:43:16 +0800 Message-Id: <1231314196.2711.48.camel@ymzhang> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 (2.22.1-2.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4982 Lines: 117 On Mon, 2008-12-08 at 12:49 +0100, Ingo Molnar wrote: > * Arjan van de Ven wrote: > > > On Mon, 8 Dec 2008 02:22:12 +0100 > > Ingo Molnar wrote: > > > > > > > > [ Performance counters are special hardware registers available on > > > most modern CPUs. These register count the number of certain types of > > > hw events: such as instructions executed, cachemisses suffered, or > > > branches mis-predicted, without slowing down the kernel or > > > applications. These registers can also trigger interrupts when a > > > threshold number of events have passed - and can thus be used to > > > profile the code that runs on that CPU. ] > > > > > > This is version 2 of our Performance Counters subsystem > > > implementation. > > > > > > The biggest user-visible change in this release is a new user-space > > > text-mode profiling utility that is based on this code: KernelTop. > > > > > > KernelTop can be downloaded from: > > > > > > http://redhat.com/~mingo/perfcounters/kerneltop.c > > > > > > It's a standalone .c file that needs no extra libraries - it only > > > needs a CONFIG_PERF_COUNTERS=y kernel to run on. > > > > > > This utility is intended for kernel developers - it's basically a > > > dynamic kernel profiler that gets hardware counter events dispatched > > > to it continuously, which it feeds into a histogram and outputs it > > > periodically. > > > > > > > I played with this a little, and while it works neat, I wanted a > > feature added where it shows a detailed profile for the top function. > > ah, very nice idea! > > > I've hacked this in quickly (the usability isn't all that great yet) > > and put the source code up at > > > > http://www.tglx.de/~arjan/kerneltop-0.02.tar.gz > > ok, picked it up :-) Ingo, I try to use patch V5 and the latest kerneltop to collect some cachemiss data. It seems kerneltop just shows the first instruction ip address of functions. Does the latest kerneltop include the enhancement from Arjan? As you know, with oprofile, we can get detailed instrument ip address which causes the cache miss although the ip address should go back one instruction mostly. > > > with this it looks like this: > > > > $ sudo ./kerneltop --vmlinux=/home/arjan/linux-2.6.git/vmlinux > > > > ------------------------------------------------------------------------------ > > KernelTop: 274 irqs/sec [NMI, 1000000 cycles], (all, 2 CPUs) > > ------------------------------------------------------------------------------ > > > > events RIP kernel function > > ______ ________________ _______________ > > > > 230 - 00000000c04189e9 : read_hpet > > 82 - 00000000c0409439 : mwait_idle_with_hints > > 77 - 00000000c051a7b7 : acpi_os_read_port > > 52 - 00000000c053cb3a : acpi_idle_enter_bm > > 38 - 00000000c0418d93 : hpet_next_event > > 19 - 00000000c051a802 : acpi_os_write_port > > 14 - 00000000c04f8704 : __copy_to_user_ll > > 13 - 00000000c0460c20 : get_page_from_freelist > > 7 - 00000000c041c96c : kunmap_atomic > > 5 - 00000000c06a30d2 : _spin_lock [joydev] > > 4 - 00000000c04f79b7 : vsnprintf [snd_seq] > > 4 - 00000000c06a3048 : _spin_lock_irqsave [pcspkr] > > 3 - 00000000c0403b3c : irq_entries_start > > 3 - 00000000c0423fee : run_rebalance_domains > > 3 - 00000000c0425e2c : scheduler_tick > > 3 - 00000000c0430938 : get_next_timer_interrupt > > 3 - 00000000c043cdfa : __update_sched_clock > > 3 - 00000000c0448b14 : update_iter > > 2 - 00000000c04304bd : run_timer_softirq > > > > Showing details for read_hpet > > 0 c04189e9 : > > 2 c04189e9: a1 b0 e0 89 c0 mov 0xc089e0b0,%eax > > 0 > > 0 /* > > 0 * Clock source related code > > 0 */ > > 0 static cycle_t read_hpet(void) > > 0 { > > 1 c04189ee: 55 push %ebp > > 0 c04189ef: 89 e5 mov %esp,%ebp > > 1 c04189f1: 05 f0 00 00 00 add $0xf0,%eax > > 0 c04189f6: 8b 00 mov (%eax),%eax > > 0 return (cycle_t)hpet_readl(HPET_COUNTER); > > 0 } > > 300 c04189f8: 31 d2 xor %edx,%edx > > 0 c04189fa: 5d pop %ebp > > 0 c04189fb: c3 ret > > 0 > Just like above detailed information. Thanks, Yanmin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/