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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 87A5CC433E0 for ; Tue, 16 Mar 2021 21:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 545B964FA8 for ; Tue, 16 Mar 2021 21:26:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229526AbhCPVZy (ORCPT ); Tue, 16 Mar 2021 17:25:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:45110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229494AbhCPVZf (ORCPT ); Tue, 16 Mar 2021 17:25:35 -0400 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 0714A64E76; Tue, 16 Mar 2021 21:25:34 +0000 (UTC) Date: Tue, 16 Mar 2021 17:25:33 -0400 From: Steven Rostedt To: "Tzvetomir Stoyanov (VMware)" Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH 09/12] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file Message-ID: <20210316172533.221e05c1@gandalf.local.home> In-Reply-To: <20210315061832.168495-10-tz.stoyanov@gmail.com> References: <20210315061832.168495-1-tz.stoyanov@gmail.com> <20210315061832.168495-10-tz.stoyanov@gmail.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Mon, 15 Mar 2021 08:18:29 +0200 "Tzvetomir Stoyanov (VMware)" wrote: > If there is information for TSC to nanoseconds conversion in the trace > file metadata, use it to recalculate the timestamps of all events. > > Signed-off-by: Tzvetomir Stoyanov (VMware) > --- > lib/trace-cmd/trace-input.c | 28 ++++++++++++++++++++++++---- > 1 file changed, 24 insertions(+), 4 deletions(-) > > diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c > index 65081007..dc9ac1d3 100644 > --- a/lib/trace-cmd/trace-input.c > +++ b/lib/trace-cmd/trace-input.c > @@ -1276,17 +1276,37 @@ static unsigned long long timestamp_correct(unsigned long long ts, > &host->ts_samples[mid+1]); > } > I would add a comment saying that the below function was taken from the Linux kernel. -- Steve > +static unsigned long long mul_u64_u32_shr(unsigned long long a, > + unsigned long long mul, unsigned int shift) > +{ > + unsigned int ah, al; > + unsigned long long ret; > + > + al = a; > + ah = a >> 32; > + > + ret = (al * mul) >> shift; > + if (ah) > + ret += (ah * mul) << (32 - shift); > + > + return ret; > +} > + > static unsigned long long timestamp_calc(unsigned long long ts, > struct tracecmd_input *handle) > { > - unsigned long long tstamp; > + unsigned long long t; > > - tstamp = timestamp_correct(ts, handle); > + t = timestamp_correct(ts, handle); > > if (handle->ts2secs) > - tstamp *= handle->ts2secs; > + t *= handle->ts2secs; > + else if (handle->tsc_calc.mult) { > + t = mul_u64_u32_shr(t, handle->tsc_calc.mult, handle->tsc_calc.shift); > + t += handle->tsc_calc.offset; > + } > > - return tstamp; > + return t; > } > > /*