From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751436AbaKGFUc (ORCPT ); Fri, 7 Nov 2014 00:20:32 -0500 Received: from lgeamrelo02.lge.com ([156.147.1.126]:33223 "EHLO lgeamrelo02.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750945AbaKGFUa (ORCPT ); Fri, 7 Nov 2014 00:20:30 -0500 X-Original-SENDERIP: 10.177.222.235 X-Original-MAILFROM: namhyung@kernel.org From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Peter Zijlstra , Ingo Molnar , Paul Mackerras , Namhyung Kim , Namhyung Kim , LKML , Jiri Olsa , Adrian Hunter , David Ahern Subject: [PATCH 1/3] perf tools: Allow vmlinux to fallback to kallsyms on NO_LIBELF=1 Date: Fri, 7 Nov 2014 14:20:04 +0900 Message-Id: <1415337606-2186-1-git-send-email-namhyung@kernel.org> X-Mailer: git-send-email 2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When libelf is not used, perf cannot not show symbol names since it doesn't access the ELF symbol table. But kernel is different as it can fallback to kallsyms. It worked w/o libelf, but recent change to use vmlinux for kernel symbols break it. With this change, it now can show kernel symbols again: # Overhead Command Shared Object Symbol # ........ ....... ................. ........................ # 34.51% swapper [kernel.kallsyms] [k] intel_idle 12.54% perf [kernel.kallsyms] [k] generic_exec_single 10.11% swapper [kernel.kallsyms] [k] int_sqrt 9.83% swapper [kernel.kallsyms] [k] hrtimer_interrupt 7.25% emacs [kernel.kallsyms] [k] __switch_to 7.06% sleep [kernel.kallsyms] [k] find_next_iomem_res 7.02% swapper [kernel.kallsyms] [k] run_timer_softirq 2.55% swapper [kernel.kallsyms] [k] _raw_spin_unlock_irq 1.90% swapper [kernel.kallsyms] [k] lapic_next_deadline 1.75% swapper [kernel.kallsyms] [k] native_sched_clock 1.49% swapper [kernel.kallsyms] [k] __schedule 1.20% swapper [kernel.kallsyms] [k] read_tsc 1.10% sleep [kernel.kallsyms] [k] current_kernel_time 0.99% swapper [kernel.kallsyms] [k] pick_next_task_rt 0.36% swapper [kernel.kallsyms] [k] group_sched_in 0.24% swapper [kernel.kallsyms] [k] x86_pmu_commit_txn 0.06% swapper [kernel.kallsyms] [k] intel_pmu_enable_all 0.03% perf [kernel.kallsyms] [k] intel_pmu_enable_all Reported-by: Peter Zijlstra Cc: Adrian Hunter Signed-off-by: Namhyung Kim --- tools/perf/util/symbol-minimal.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c index c9541fea9514..226cf41ed7e6 100644 --- a/tools/perf/util/symbol-minimal.c +++ b/tools/perf/util/symbol-minimal.c @@ -335,6 +335,9 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused, unsigned char *build_id[BUILD_ID_SIZE]; int ret; + if (dso->kernel) + return 0; /* always use kallsyms */ + ret = fd__is_64_bit(ss->fd); if (ret >= 0) dso->is_64_bit = ret; -- 2.1.2