Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752736AbbETGxL (ORCPT ); Wed, 20 May 2015 02:53:11 -0400 Received: from mail-ig0-f173.google.com ([209.85.213.173]:38311 "EHLO mail-ig0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751383AbbETGxI (ORCPT ); Wed, 20 May 2015 02:53:08 -0400 MIME-Version: 1.0 X-Originating-IP: [2a02:a03f:22d1:fe00:eab1:fcff:fe17:ff98] In-Reply-To: <20150519165202.GA21251@e104818-lin.cambridge.arm.com> References: <20150508153758.GG25587@arm.com> <1431256060-161483-1-git-send-email-houpengyang@huawei.com> <20150519165202.GA21251@e104818-lin.cambridge.arm.com> Date: Wed, 20 May 2015 08:53:07 +0200 Message-ID: Subject: Re: [PATCH v5] arm64: perf: Fix callchain parse error with kernel tracepoint events From: Jean Pihet To: Catalin Marinas , Will Deacon Cc: Hou Pengyang , wangnan0@huawei.com, Peter Zijlstra , LKML , acme@kernel.org, mingo@redhat.com, Paul Mackerras , linux-arm Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2148 Lines: 59 Hi Catalin, Will, On Tue, May 19, 2015 at 6:52 PM, Catalin Marinas wrote: > On Sun, May 10, 2015 at 11:07:40AM +0000, Hou Pengyang wrote: >> For ARM64, when tracing with tracepoint events, the IP and pstate are set >> to 0, preventing the perf code parsing the callchain and resolving the >> symbols correctly. >> >> ./perf record -e sched:sched_switch -g --call-graph dwarf ls >> [ perf record: Captured and wrote 0.146 MB perf.data ] >> ./perf report -f >> Samples: 194 of event 'sched:sched_switch', Event count (approx.): 194 >> Children Self Command Shared Object Symbol >> 100.00% 100.00% ls [unknown] [.] 0000000000000000 >> >> The fix is to implement perf_arch_fetch_caller_regs for ARM64, which fills >> several necessary registers used for callchain unwinding, including pc,sp, >> fp and spsr . >> >> With this patch, callchain can be parsed correctly as follows: >> >> ...... >> + 2.63% 0.00% ls [kernel.kallsyms] [k] vfs_symlink >> + 2.63% 0.00% ls [kernel.kallsyms] [k] follow_down >> + 2.63% 0.00% ls [kernel.kallsyms] [k] pfkey_get >> + 2.63% 0.00% ls [kernel.kallsyms] [k] do_execveat_common.isra.33 >> - 2.63% 0.00% ls [kernel.kallsyms] [k] pfkey_send_policy_notify >> pfkey_send_policy_notify >> pfkey_get >> v9fs_vfs_rename >> page_follow_link_light >> link_path_walk >> el0_svc_naked >> ....... >> >> Signed-off-by: Hou Pengyang >> Acked-by: Will Deacon > > Queued for 4.2. Thanks. Nice to see this one going out, finally. Cheers, Jean > > -- > Catalin > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- 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/