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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 5D800ECDE44 for ; Wed, 31 Oct 2018 13:01:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22DA920664 for ; Wed, 31 Oct 2018 13:01:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22DA920664 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1729332AbeJaV7q (ORCPT ); Wed, 31 Oct 2018 17:59:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48818 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729128AbeJaV7q (ORCPT ); Wed, 31 Oct 2018 17:59:46 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2998CC0495A6; Wed, 31 Oct 2018 13:01:50 +0000 (UTC) Received: from krava (unknown [10.43.17.150]) by smtp.corp.redhat.com (Postfix) with SMTP id 6DCC368393; Wed, 31 Oct 2018 13:01:47 +0000 (UTC) Date: Wed, 31 Oct 2018 14:01:38 +0100 From: Jiri Olsa To: David Miller Cc: acme@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf: Don't clone maps from parent when synthesizing forks Message-ID: <20181031130138.GA13216@krava> References: <20181030.222404.2085088822877051075.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181030.222404.2085088822877051075.davem@davemloft.net> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Wed, 31 Oct 2018 13:01:50 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 30, 2018 at 10:24:04PM -0700, David Miller wrote: SNIP > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 111ae858cbcb..214b7979c4e7 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) > @@ -1737,8 +1738,11 @@ int machine__process_fork_event(struct machine *machine, union perf_event *event > thread = machine__findnew_thread(machine, event->fork.pid, > event->fork.tid); > > + if (event->fork.header.misc & PERF_RECORD_MISC_FORK_EXEC) > + do_maps_clone = false; could you please put some comment in here shortly explaining the reason behind this flag > + > 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..54b2c9ceba9f 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 +342,14 @@ 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) > + if (do_maps_clone && > + map_groups__clone(thread, parent->mg) < 0) > return -ENOMEM; > - > return 0; we could move all this into one line: return do_maps_clone ? map_groups__clone(thread, parent->mg) : 0; thanks, jirka > } > > -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 +362,7 @@ 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 07606aa6998d..7e30fe99b74b 100644 > --- a/tools/perf/util/thread.h > +++ b/tools/perf/util/thread.h > @@ -87,7 +87,7 @@ 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);