From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754378Ab2GJVsj (ORCPT ); Tue, 10 Jul 2012 17:48:39 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:49801 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754276Ab2GJVse (ORCPT ); Tue, 10 Jul 2012 17:48:34 -0400 From: David Ahern To: acme@ghostprotocols.net, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: David Ahern , Arnaldo Carvalho de Melo , Jiri Olsa , Namhyung Kim , Frederic Weisbecker , Peter Zijlstra Subject: [PATCH 4/4] perf kvm: fix bug resolving guest kernel syms Date: Tue, 10 Jul 2012 15:48:14 -0600 Message-Id: <1341956894-69284-5-git-send-email-dsahern@gmail.com> X-Mailer: git-send-email 1.7.10.1 In-Reply-To: <1341956894-69284-1-git-send-email-dsahern@gmail.com> References: <1341956894-69284-1-git-send-email-dsahern@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Guest kernel symbols are not resolved despite passing the information needed to resolve them. e.g., perf kvm --guest --guestmount=/tmp/guest-mount record -a -- sleep 1 perf kvm --guest --guestmount=/tmp/guest-mount report --stdio 36.55% [guest/11399] [unknown] [g] 0xffffffff81600bc8 33.19% [guest/10474] [unknown] [g] 0x00000000c0116e00 30.26% [guest/11094] [unknown] [g] 0xffffffff8100a288 43.69% [guest/10474] [unknown] [g] 0x00000000c0103d90 37.38% [guest/11399] [unknown] [g] 0xffffffff81600bc8 12.24% [guest/11094] [unknown] [g] 0xffffffff810aa91d 6.69% [guest/11094] [unknown] [u] 0x00007fa784d721c3 which is just pathetic. After a maddening 2 days sifting through perf minutia I found it -- id_hdr_size is not initialized for guest machines. This shows up on the report side as random garbage for the cpu and timestamp, e.g., 29816 7310572949125804849 0x1ac0 [0x50]: PERF_RECORD_MMAP ... that messes up the sample sorting such that synthesized guest maps are processed last. With this patch you get a much more helpful report: 12.11% [guest/11399] [guest.kernel.kallsyms.11399] [g] irqtime_account_process_tick 10.58% [guest/11399] [guest.kernel.kallsyms.11399] [g] run_timer_softirq 6.95% [guest/11094] [guest.kernel.kallsyms.11094] [g] printk_needs_cpu 6.50% [guest/11094] [guest.kernel.kallsyms.11094] [g] do_timer 6.45% [guest/11399] [guest.kernel.kallsyms.11399] [g] idle_balance 4.90% [guest/11094] [guest.kernel.kallsyms.11094] [g] native_read_tsc ... Signed-off-by: David Ahern Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Frederic Weisbecker Cc: Peter Zijlstra --- tools/perf/util/map.c | 24 ++++++++++++++++++++++++ tools/perf/util/map.h | 1 + tools/perf/util/session.c | 1 + 3 files changed, 26 insertions(+) diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index 641377e..da3411b 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -730,3 +730,27 @@ char *machine__mmap_name(struct machine *self, char *bf, size_t size) return bf; } + +void machines__set_id_hdr_size(struct rb_root *self, u16 id_hdr_size) +{ + struct rb_node *p; + struct machine *machine; + + p = self->rb_node; + while (p != NULL) { + machine = rb_entry(p, struct machine, rb_node); + machine->id_hdr_size = id_hdr_size; + p = rb_next(p); + } + + p = self->rb_node; + if (p) + p = rb_prev(p); + while (p != NULL) { + machine = rb_entry(p, struct machine, rb_node); + machine->id_hdr_size = id_hdr_size; + p = rb_prev(p); + } + + return; +} diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index 81371ba..7159b3c 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -151,6 +151,7 @@ struct machine *machines__add(struct rb_root *self, pid_t pid, struct machine *machines__find_host(struct rb_root *self); struct machine *machines__find(struct rb_root *self, pid_t pid); struct machine *machines__findnew(struct rb_root *self, pid_t pid); +void machines__set_id_hdr_size(struct rb_root *self, u16 id_hdr_size); char *machine__mmap_name(struct machine *self, char *bf, size_t size); int machine__init(struct machine *self, const char *root_dir, pid_t pid); void machine__exit(struct machine *self); diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 7c31623..fcf9498 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -86,6 +86,7 @@ void perf_session__update_sample_type(struct perf_session *self) self->sample_id_all = perf_evlist__sample_id_all(self->evlist); self->id_hdr_size = perf_evlist__id_hdr_size(self->evlist); self->host_machine.id_hdr_size = self->id_hdr_size; + machines__set_id_hdr_size(&self->machines, self->id_hdr_size); } int perf_session__create_kernel_maps(struct perf_session *self) -- 1.7.10.1