From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934466AbeCENq5 (ORCPT ); Mon, 5 Mar 2018 08:46:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:47856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933799AbeCENqy (ORCPT ); Mon, 5 Mar 2018 08:46:54 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 501AE206B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Mon, 5 Mar 2018 10:46:52 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: kan.liang@linux.intel.com, Ingo Molnar , linux-kernel@vger.kernel.org, namhyung@kernel.org, wangnan0@huawei.com, ak@linux.intel.com Subject: Re: [PATCH 02/14] perf trace: Apply new perf_mmap__read_event() interface Message-ID: <20180305134652.GF30054@kernel.org> References: <1519945751-37786-1-git-send-email-kan.liang@linux.intel.com> <1519945751-37786-2-git-send-email-kan.liang@linux.intel.com> <20180302233022.GB8970@krava> <20180305130339.GE30054@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180305130339.GE30054@kernel.org> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Mar 05, 2018 at 10:03:39AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Sat, Mar 03, 2018 at 12:30:22AM +0100, Jiri Olsa escreveu: > > On Thu, Mar 01, 2018 at 06:08:59PM -0500, kan.liang@linux.intel.com wrote: > > > From: Kan Liang > > > The perf trace still use the legacy interface. > > > +++ b/tools/perf/builtin-trace.c > > > @@ -2472,8 +2472,14 @@ static int trace__run(struct trace *trace, int argc, const char **argv) > > > > > > for (i = 0; i < evlist->nr_mmaps; i++) { > > > union perf_event *event; > > > + struct perf_mmap *md; > > > + u64 end, start; > > > > > > - while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) { > > > + md = &evlist->mmap[i]; > > > + if (perf_mmap__read_init(md, 0, &start, &end) < 0) > > > + continue; > > > + > > > + while ((event = perf_mmap__read_event(md, 0, &start, end)) != NULL) { > > > struct perf_sample sample; > > > > > > ++trace->nr_events; > > > @@ -2486,7 +2492,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv) > > > > > > trace__handle_event(trace, event, &sample); > > > next_event: > > > - perf_evlist__mmap_consume(evlist, i); > > > + perf_mmap__consume(md, 0); > > > > could you call this with 'false' instead of 0, it's 'bool overwrite' > > applies also to the rest of the patchset > > I'm doing this, the argument is 'bool', so the value should be false or > true, even '0' being way shorter... While doing that I wonder why is that we can't do it without those explicit start/end variables in all the call sites and passing overwrite, start and end as parameters... Can't we just add 'overwrite, 'start' and 'end' to struct perf_mmap, then have perf_mmap__read_init() with just 'md' and 'overwrite' as parameters, initialize md->{start,end} and set md->overwrite to the 'overwrite' parameter in 'perf_mmap__read_init()' and then use just md as parameters for both perf_mmap__read_event() and perf_mmap__consume()? What am I missing to have this much simpler without all this boilerplate? Anyway, finishing the s/0/false/g, will leave this for later, but please comment on it. - Arnaldo