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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 99137C433F5 for ; Thu, 9 Sep 2021 18:04:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 793FE6113A for ; Thu, 9 Sep 2021 18:04:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243214AbhIISFy (ORCPT ); Thu, 9 Sep 2021 14:05:54 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:52506 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242867AbhIISFu (ORCPT ); Thu, 9 Sep 2021 14:05:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631210679; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=7EX0cSLb6fTGp/aQMn3dNWmpKkFZMxnIlL1OL2aIQc8=; b=JrHX5NqdEJj2/+LpfacRoLxKnnPZwtDJ7ho//ASm1GoaEGrBwhlpju/e+l+GdtC1MTd79C FcAfv36JtkU4xNRO6e7cVBoa7SpsmBIYcQJ2PODHy8k7SMaWuTdlHQDRfCRz2mUi1xXIMo z2ZIjw/7n0NosaRgMNdaXLZzRab82bg= Received: from mail-io1-f72.google.com (mail-io1-f72.google.com [209.85.166.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-533-rP7VLreFN36GukaNMw3rzg-1; Thu, 09 Sep 2021 14:04:38 -0400 X-MC-Unique: rP7VLreFN36GukaNMw3rzg-1 Received: by mail-io1-f72.google.com with SMTP id a9-20020a5ec309000000b005baa3f77016so2586098iok.1 for ; Thu, 09 Sep 2021 11:04:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=7EX0cSLb6fTGp/aQMn3dNWmpKkFZMxnIlL1OL2aIQc8=; b=6cYq7mdlhLtf4J19rGb9z7K7teqIhBW/QRzHThiyjkU2WVpJGRrRdwAEDCV8+Co9RP FYHt6J5BZ2txkIyWIvkZuJKQv8gAcvavilp0jr2GwpJicgUxhAkmtJH/j9l/hKQ6q1s8 OyXlgJ+WM9q+H9z9pqUktnSMoFH0RQsiWh4ZZ8LTE/Wdbupn/KOEWXcxIOSPzXUuKlc0 Ql/9JDlUIhwdBNPpPbIsMF9unwf8c2cN9CVrete5WTZDDpMkeeP7VK7xMCl/xG41MlM7 zApUqmUxeNzbGrCOT+LTQtxKGjZ2cEUH0kvIr1JxBMhVlsByOUjme/F54T3geCgY19ik +yPA== X-Gm-Message-State: AOAM530uQ4ren4sm/SklBTsCu8+52k6l3Cme2Ha4ekcPsBDlxYYhFLH8 JFyCPeNqjiODSix0sAwTgVHlRu7kxeVGhvv98/LyBOEFVPxV1KdbDDNqH7VQ4BQHOB5VyeZUD6D hqQ9U402UruTBP1HfmaSECQoFVcg= X-Received: by 2002:a92:d406:: with SMTP id q6mr3360970ilm.166.1631210677346; Thu, 09 Sep 2021 11:04:37 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy+i50MRf0tnY1PlxTHNT8FAok8bG1jb4hFwhkxISuTk0fI22H/MuAIe++gnCOPclpigWsSwQ== X-Received: by 2002:a92:d406:: with SMTP id q6mr3360955ilm.166.1631210677096; Thu, 09 Sep 2021 11:04:37 -0700 (PDT) Received: from t490s ([2607:fea8:56a3:500::ad7f]) by smtp.gmail.com with ESMTPSA id f14sm666014ile.82.2021.09.09.11.04.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Sep 2021 11:04:36 -0700 (PDT) Date: Thu, 9 Sep 2021 14:04:35 -0400 From: Peter Xu To: nsaenzju@redhat.com Cc: linux-rt-users@vger.kernel.org, williams@redhat.com, jkacur@redhat.com Subject: Re: [PATCH 3/3] oslat: Allow for arch specific timer frequency measurements Message-ID: References: <20210908100209.118609-1-nsaenzju@redhat.com> <20210908100209.118609-3-nsaenzju@redhat.com> <2518d9f959f16de10229a67e4917699f8605d947.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <2518d9f959f16de10229a67e4917699f8605d947.camel@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org On Thu, Sep 09, 2021 at 12:29:17PM +0200, nsaenzju@redhat.com wrote: > > I'm also wondering the diff between the two methods on arm64 and whether > > there's a huge difference on the numbers. > > There isn't much, after rounding the end result in MHz is the same regardless > of the method used. IIUC, gettimeoftheday() uses the frequency register's value > to scale the counter measurements. So it makes sense for the results to be > coherent. > > I figured it's cleaner to get the data from the source instead of inferring it > with extra math. Fair enough. Thanks, -- Peter Xu