From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A419ECDE44 for ; Wed, 31 Oct 2018 22:12:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43D7320664 for ; Wed, 31 Oct 2018 22:12:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43D7320664 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727524AbeKAHMS (ORCPT ); Thu, 1 Nov 2018 03:12:18 -0400 Received: from terminus.zytor.com ([198.137.202.136]:59481 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725755AbeKAHMS (ORCPT ); Thu, 1 Nov 2018 03:12:18 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w9VMCCA02561736 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 31 Oct 2018 15:12:12 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w9VMCCqS2561729; Wed, 31 Oct 2018 15:12:12 -0700 Date: Wed, 31 Oct 2018 15:12:12 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for David Miller Message-ID: Cc: acme@redhat.com, dzickus@redhat.com, jolsa@redhat.com, davem@davemloft.net, jmario@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com Reply-To: linux-kernel@vger.kernel.org, tglx@linutronix.de, jmario@redhat.com, hpa@zytor.com, mingo@kernel.org, acme@redhat.com, davem@davemloft.net, jolsa@redhat.com, dzickus@redhat.com In-Reply-To: <20181030.222404.2085088822877051075.davem@davemloft.net> References: <20181030.222404.2085088822877051075.davem@davemloft.net> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf tools: Don't clone maps from parent when synthesizing forks Git-Commit-ID: 4f8f382e635707ddaddf8269a116e4f8cc8835c0 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4f8f382e635707ddaddf8269a116e4f8cc8835c0 Gitweb: https://git.kernel.org/tip/4f8f382e635707ddaddf8269a116e4f8cc8835c0 Author: David Miller AuthorDate: Tue, 30 Oct 2018 22:24:04 -0700 Committer: Arnaldo Carvalho de Melo CommitDate: Wed, 31 Oct 2018 10:18:01 -0300 perf tools: Don't clone maps from parent when synthesizing forks When synthesizing FORK events, we are trying to create thread objects for the already running tasks on the machine. Normally, for a kernel FORK event, we want to clone the parent's maps because that is what the kernel just did. But when synthesizing, this should not be done. If we do, we end up with overlapping maps as we process the sythesized MMAP2 events that get delivered shortly thereafter. Use the FORK event misc flags in an internal way to signal this situation, so we can elide the map clone when appropriate. Signed-off-by: David S. Miller Cc: Don Zickus Cc: Jiri Olsa Cc: Joe Mario Link: http://lkml.kernel.org/r/20181030.222404.2085088822877051075.davem@davemloft.net [ Added comment about flag use in machine__process_fork_event(), use ternary op in thread__clone_map_groups() as suggested by Jiri ] Signed-off-by: Arnaldo Carvalho de Melo --- include/uapi/linux/perf_event.h | 2 ++ tools/include/uapi/linux/perf_event.h | 2 ++ tools/perf/util/event.c | 1 + tools/perf/util/machine.c | 19 ++++++++++++++++++- tools/perf/util/thread.c | 13 +++++-------- tools/perf/util/thread.h | 2 +- 6 files changed, 29 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index f35eb72739c0..9de8780ac8d9 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -646,10 +646,12 @@ struct perf_event_mmap_page { * * PERF_RECORD_MISC_MMAP_DATA - PERF_RECORD_MMAP* events * PERF_RECORD_MISC_COMM_EXEC - PERF_RECORD_COMM event + * PERF_RECORD_MISC_FORK_EXEC - PERF_RECORD_FORK event (perf internal) * PERF_RECORD_MISC_SWITCH_OUT - PERF_RECORD_SWITCH* events */ #define PERF_RECORD_MISC_MMAP_DATA (1 << 13) #define PERF_RECORD_MISC_COMM_EXEC (1 << 13) +#define PERF_RECORD_MISC_FORK_EXEC (1 << 13) #define PERF_RECORD_MISC_SWITCH_OUT (1 << 13) /* * These PERF_RECORD_MISC_* flags below are safely reused diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index f35eb72739c0..9de8780ac8d9 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -646,10 +646,12 @@ struct perf_event_mmap_page { * * PERF_RECORD_MISC_MMAP_DATA - PERF_RECORD_MMAP* events * PERF_RECORD_MISC_COMM_EXEC - PERF_RECORD_COMM event + * PERF_RECORD_MISC_FORK_EXEC - PERF_RECORD_FORK event (perf internal) * PERF_RECORD_MISC_SWITCH_OUT - PERF_RECORD_SWITCH* events */ #define PERF_RECORD_MISC_MMAP_DATA (1 << 13) #define PERF_RECORD_MISC_COMM_EXEC (1 << 13) +#define PERF_RECORD_MISC_FORK_EXEC (1 << 13) #define PERF_RECORD_MISC_SWITCH_OUT (1 << 13) /* * These PERF_RECORD_MISC_* flags below are safely reused diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c index bc646185f8d9..e9c108a6b1c3 100644 --- a/tools/perf/util/event.c +++ b/tools/perf/util/event.c @@ -308,6 +308,7 @@ static int perf_event__synthesize_fork(struct perf_tool *tool, event->fork.pid = tgid; event->fork.tid = pid; event->fork.header.type = PERF_RECORD_FORK; + event->fork.header.misc = PERF_RECORD_MISC_FORK_EXEC; event->fork.header.size = (sizeof(event->fork) + machine->id_hdr_size); diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 8ee8ab39d8ac..8f36ce813bc5 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1708,6 +1708,7 @@ int machine__process_fork_event(struct machine *machine, union perf_event *event struct thread *parent = machine__findnew_thread(machine, event->fork.ppid, event->fork.ptid); + bool do_maps_clone = true; int err = 0; if (dump_trace) @@ -1736,9 +1737,25 @@ int machine__process_fork_event(struct machine *machine, union perf_event *event thread = machine__findnew_thread(machine, event->fork.pid, event->fork.tid); + /* + * When synthesizing FORK events, we are trying to create thread + * objects for the already running tasks on the machine. + * + * Normally, for a kernel FORK event, we want to clone the parent's + * maps because that is what the kernel just did. + * + * But when synthesizing, this should not be done. If we do, we end up + * with overlapping maps as we process the sythesized MMAP2 events that + * get delivered shortly thereafter. + * + * Use the FORK event misc flags in an internal way to signal this + * situation, so we can elide the map clone when appropriate. + */ + if (event->fork.header.misc & PERF_RECORD_MISC_FORK_EXEC) + do_maps_clone = false; if (thread == NULL || parent == NULL || - thread__fork(thread, parent, sample->time) < 0) { + thread__fork(thread, parent, sample->time, do_maps_clone) < 0) { dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n"); err = -1; } diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 2048d393ece6..3d9ed7d0e281 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -330,7 +330,8 @@ static int thread__prepare_access(struct thread *thread) } static int thread__clone_map_groups(struct thread *thread, - struct thread *parent) + struct thread *parent, + bool do_maps_clone) { /* This is new thread, we share map groups for process. */ if (thread->pid_ == parent->pid_) @@ -341,15 +342,11 @@ static int thread__clone_map_groups(struct thread *thread, thread->pid_, thread->tid, parent->pid_, parent->tid); return 0; } - /* But this one is new process, copy maps. */ - if (map_groups__clone(thread, parent->mg) < 0) - return -ENOMEM; - - return 0; + return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0; } -int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp) +int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone) { if (parent->comm_set) { const char *comm = thread__comm_str(parent); @@ -362,7 +359,7 @@ int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp) } thread->ppid = parent->tid; - return thread__clone_map_groups(thread, parent); + return thread__clone_map_groups(thread, parent, do_maps_clone); } void thread__find_cpumode_addr_location(struct thread *thread, u64 addr, diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index 36c09a9904e6..30e2b4c165fe 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -89,7 +89,7 @@ struct comm *thread__comm(const struct thread *thread); struct comm *thread__exec_comm(const struct thread *thread); const char *thread__comm_str(const struct thread *thread); int thread__insert_map(struct thread *thread, struct map *map); -int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp); +int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone); size_t thread__fprintf(struct thread *thread, FILE *fp); struct thread *thread__main_thread(struct machine *machine, struct thread *thread);