From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Olsa Subject: Re: [PATCH 2/2] perf script: flush output stream after events in verbose mode Date: Mon, 22 Oct 2018 15:54:30 +0200 Message-ID: <20181022135430.GA2945@krava> References: <20181021191424.16183-1-milian.wolff@kdab.com> <4444017.LnbBPIbh24@agathebauer> <20181022101618.GH2452@krava> <1755624.MxyOU8z0WO@agathebauer> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1755624.MxyOU8z0WO@agathebauer> Sender: linux-kernel-owner@vger.kernel.org To: Milian Wolff Cc: acme@kernel.org, jolsa@kernel.org, Linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org List-Id: linux-perf-users.vger.kernel.org On Mon, Oct 22, 2018 at 12:38:57PM +0200, Milian Wolff wrote: SNIP > > > > > diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c > > > > > index bd468b90801b..ca09b7d2adb7 100644 > > > > > --- a/tools/perf/builtin-script.c > > > > > +++ b/tools/perf/builtin-script.c > > > > > @@ -1737,6 +1737,9 @@ static void process_event(struct perf_script > > > > > *script, > > > > > > > > > > if (PRINT_FIELD(METRIC)) > > > > > > > > > > perf_sample__fprint_metric(script, thread, evsel, > sample, fp); > > > > > > > > > > + > > > > > + if (verbose) > > > > > + fflush(fp); > > > > > > > > should we call fflush(NULL) to dump all the streams? > > > > > > > > the verbose goes to stderr and fp seems to be stdout byt default > > > > > > stderr isn't buffered, so we don't need to flush it. So personally, I > > > don't > > > see a need to dump all streams - fp should be enough? Can you maybe > > > explain > > > where it would be required to flush more buffers? > > > > hum, did not know stderr wasn't buffer > > > > I think there's perf script feature to store the events data to > > separate files per each event.. but I guess we don't need to > > flush them.. we just need to have stdout and stderr in sync IIUC > > Exactly, and that's achieved with this patch form what I see :) Or should we > maybe instead call > > setbuf(fp, NULL); > > in verbose mode? I think your solution is ok Acked-by: Jiri Olsa thanks, jirka