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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 8FF45C43603 for ; Wed, 4 Dec 2019 20:10:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 58D912077B for ; Wed, 4 Dec 2019 20:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727887AbfLDUKA (ORCPT ); Wed, 4 Dec 2019 15:10:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:60554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727033AbfLDUKA (ORCPT ); Wed, 4 Dec 2019 15:10:00 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6E7B0205ED; Wed, 4 Dec 2019 20:09:59 +0000 (UTC) Date: Wed, 4 Dec 2019 15:09:57 -0500 From: Steven Rostedt To: "Tzvetomir Stoyanov (VMware)" Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH v17 05/18] trace-cmd: Add new library API for local CPU count Message-ID: <20191204150957.07cef7d1@gandalf.local.home> In-Reply-To: <20191203103522.482684-6-tz.stoyanov@gmail.com> References: <20191203103522.482684-1-tz.stoyanov@gmail.com> <20191203103522.482684-6-tz.stoyanov@gmail.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Tue, 3 Dec 2019 12:35:09 +0200 "Tzvetomir Stoyanov (VMware)" wrote: > In order to reuse the code, the function detecting the > number of local CPU is moved from trace-cmd application to > libtracecmd. The following new library API is introduced: > int tracecmd_count_cpus(void); > > Signed-off-by: Tzvetomir Stoyanov (VMware) > --- > include/trace-cmd/trace-cmd.h | 3 +++ > lib/trace-cmd/trace-util.c | 40 +++++++++++++++++++++++++++++ > tracecmd/include/trace-local.h | 2 -- > tracecmd/trace-agent.c | 2 +- > tracecmd/trace-profile.c | 2 +- > tracecmd/trace-record.c | 46 +++------------------------------- > tracecmd/trace-stat.c | 4 +-- > 7 files changed, 50 insertions(+), 49 deletions(-) > > diff --git a/include/trace-cmd/trace-cmd.h b/include/trace-cmd/trace-cmd.h > index 5287d23..5d4292e 100644 > --- a/include/trace-cmd/trace-cmd.h > +++ b/include/trace-cmd/trace-cmd.h > @@ -427,6 +427,9 @@ void tracecmd_plog(const char *fmt, ...); > void tracecmd_plog_error(const char *fmt, ...); > int tracecmd_set_logfile(char *logfile); > > +/* --- System --- */ > +int tracecmd_count_cpus(void); > + > /* --- Hack! --- */ > int tracecmd_blk_hack(struct tracecmd_input *handle); > > diff --git a/lib/trace-cmd/trace-util.c b/lib/trace-cmd/trace-util.c > index 4c70d9a..e019dce 100644 > --- a/lib/trace-cmd/trace-util.c > +++ b/lib/trace-cmd/trace-util.c > @@ -1112,6 +1112,46 @@ int tracecmd_stack_tracer_status(int *status) > return 1; /* full success */ > } > > +int tracecmd_count_cpus(void) > +{ > + FILE *fp; > + char buf[1024]; > + int cpus = 0; > + char *pbuf; > + size_t *pn; > + size_t n; > + int r; > + > + cpus = sysconf(_SC_NPROCESSORS_CONF); > + if (cpus > 0) > + return cpus; > + > + warning("sysconf could not determine number of CPUS"); As this is now a library function, probably should have a static variable here: static int once; if (!once) { once++; warning("..."); } No need to do more than one warning. > + > + /* Do the hack to figure out # of CPUS */ > + n = 1024; > + pn = &n; > + pbuf = buf; > + > + fp = fopen("/proc/cpuinfo", "r"); > + if (!fp) > + die("Can not read cpuinfo"); Need to get rid of the die(). Could be in a separate patch. Will also need to have the call sites check to see if the returned number is negative, and fail there. -- Steve > + > + while ((r = getline(&pbuf, pn, fp)) >= 0) { > + char *p; > + > + if (strncmp(buf, "processor", 9) != 0) > + continue; > + for (p = buf+9; isspace(*p); p++) > + ; > + if (*p == ':') > + cpus++; > + } > + fclose(fp); > + > + return cpus; > +} > + > /* > * tracecmd_write_file - Write in trace file > * @file: Full name of the trace file. > diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h