From patchwork Fri May 17 02:16:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 2580831 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork2.kernel.org (Postfix) with ESMTP id 34A29DFE75 for ; Fri, 17 May 2013 02:17:31 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdAEP-0007cx-P1; Fri, 17 May 2013 02:17:17 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdAEN-0004yG-1k; Fri, 17 May 2013 02:17:15 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UdAEG-0004xj-7L for linux-arm-kernel@lists.infradead.org; Fri, 17 May 2013 02:17:08 +0000 Received: from mail-vb0-f45.google.com ([209.85.212.45]) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1UdADp-0002Yn-PL for linux-arm-kernel@lists.infradead.org; Fri, 17 May 2013 02:16:41 +0000 Received: by mail-vb0-f45.google.com with SMTP id 12so1043612vbf.32 for ; Thu, 16 May 2013 19:16:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:x-received:date:message-id:subject:from:to:cc :content-type; bh=d5+CmZa5xn5ossrgYi40WMFEJ8r/HsYExosNu3fhsSc=; b=a7uufH1hIDen2mocBDc6l6Rc/IZ8yaO5HrYhaHAgY0ncl1VEHGBarrr+OMUG0xirhx 15AgzHDHRabCe2vsbEOOOKZWOsHcOTWPh/OMmFvRvNbfeaw97kdY5/Iv9H4AxbjYrgot rA3U+yWSL0C15XmMqPTGAO/QGuNhD9JKHht6TatsLjAXf9FCjUshrSyP7pcSbHzbznTT FsmlVZw2Nad8rANAGp/Cf2sqiexlnAPs/CZBmeDX/zvW5kgG9uTCWd5fUSrbzCjySVwK fLKZKotsolDKxNW0jPHibOY6MWHmR6SHLy7ZBtdswwlx8gyuC3cUlMCAcl98o2ja+c1H CCug== MIME-Version: 1.0 X-Received: by 10.52.36.115 with SMTP id p19mr7424605vdj.8.1368757000473; Thu, 16 May 2013 19:16:40 -0700 (PDT) Received: by 10.221.12.198 with HTTP; Thu, 16 May 2013 19:16:40 -0700 (PDT) Date: Fri, 17 May 2013 10:16:40 +0800 Message-ID: Subject: [Bug] ARM 'perf' regression by commit a43cb95d5 From: Ming Lei To: Tejun Heo , Peter Zijlstra , Will Deacon , Russell King - ARM Linux , Linus Torvalds X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130516_221708_449475_1FEB16A9 X-CRM114-Status: UNSURE ( 9.57 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -3.2 (---) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-3.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [91.189.89.112 listed in list.dnswl.org] -0.6 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Linux Kernel Mailing List , linux-arm-kernel X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Hi, The commit a43cb95d5(dump_stack: unify debug information printed by show_regs()) caused ARM perf regression, then 'perf top' outputs mistakenly, see [1]. The correct output should be [2], which can be got after reverting the commit or doing it partly by the one line change below: Thanks, --- Ming Lei [1], 'perf top' mistaken output Samples: 17K of event 'cpu-clock', Event count (approx.): 3516532661 97.51% [smsc95xx] [k] 0x013645b8 0.21% libc-2.15.so [.] strstr 0.14% libc-2.15.so [.] strchr 0.12% libc-2.15.so [.] strcmp 0.12% perf [.] perf_evsel__parse_sample 0.09% perf [.] symbols__insert 0.09% perf [.] dso__load_sym 0.08% perf [.] perf_top__mmap_read_idx 0.08% perf [.] symbol_filter 0.07% libc-2.15.so [.] memchr 0.07% libc-2.15.so [.] memset 0.07% perf [.] internal_cplus_demangle 0.06% perf [.] sort__dso_cmp 0.06% libc-2.15.so [.] strncmp 0.06% perf [.] add_hist_entry.isra.2 0.06% perf [.] dso__find_symbol 0.06% libc-2.15.so [.] _int_malloc 0.05% perf [.] 0x00010d60 0.04% libc-2.15.so [.] memcpy 0.04% perf [.] map__find_symbol 0.04% perf [.] rb_next 0.04% libelf-0.154.so [.] gelf_getsym [2], 'perf top' correct output Samples: 46K of event 'cpu-clock', Event count (approx.): 937128704 96.44% [kernel] [k] cpuidle_enter_state 0.19% libc-2.15.so [.] strstr 0.16% [kernel] [k] kallsyms_expand_symbol.clone.0 0.13% [kernel] [k] _raw_spin_unlock_irq 0.13% [kernel] [k] _raw_spin_unlock_irqrestore 0.10% [kernel] [k] format_decode 0.10% perf [.] perf_top__mmap_read_idx 0.10% perf [.] rb_next 0.09% perf [.] dso__find_symbol 0.08% [kernel] [k] vsnprintf 0.08% perf [.] add_hist_entry.isra.2 0.08% libc-2.15.so [.] strcmp 0.08% libc-2.15.so [.] memchr 0.07% perf [.] sort__dso_cmp 0.07% libc-2.15.so [.] strchr 0.07% [kernel] [k] number.clone.1 0.07% perf [.] map__process_kallsym_symbol 0.06% [kernel] [k] memcpy 0.05% perf [.] perf_evsel__parse_sample 0.05% libc-2.15.so [.] _int_malloc 0.05% libc-2.15.so [.] memcpy 0.05% perf [.] perf_event__preprocess_sample diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index f219703..89bc3a4 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -225,7 +225,7 @@ void __show_regs(struct pt_regs *regs) unsigned long flags; char buf[64]; - show_regs_print_info(KERN_DEFAULT); + //show_regs_print_info(KERN_DEFAULT); Looks a bit weird, anyone can give a hint?