Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp4126170imu; Sat, 24 Nov 2018 19:26:14 -0800 (PST) X-Google-Smtp-Source: AFSGD/XDkwl+iVMnXZOnLynkdXqvqsP79UH4wgn+dcxtU+3XYaBheWA+weOMQCI4cVeNERd9SJOU X-Received: by 2002:a63:6704:: with SMTP id b4mr19956666pgc.100.1543116374457; Sat, 24 Nov 2018 19:26:14 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1543116374; cv=none; d=google.com; s=arc-20160816; b=HZ9T8iEqsYzt559veEQmt91XkwFfWoxzjSFiGkC4mRHhqTRlj3/MXxoSshj0WRThmB +6QMpxEM3OSWA+lHaIFlEzSJXFnUyn/+a+bQtxZyzxwWMj487tL4F11qw2wCCdooIAlC aT1GuER/7PFRUZ4cunMx04OBE6oljjIW04C7in8AsyyOo2/bVmI9vID8/sp62ws6v7eN pDAHbwORjO0hDeNu9pY+HOFpbESc4X3qYuTYuVL+IPW+7GpvStC6AE+zDVUmTFQtzQnJ l73XP5QwX2Ns4gjZzjEIOP+hA56t0Takcn7iP2eqx0S1rEdhKijMeeEX/eHIEYHoSqlv jY9Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:mime-version:references:message-id :in-reply-to:subject:cc:to:from:date; bh=+CrSiSABGHGa/CcYFkxVnNlrUUvpjbrDADyUGR1icVU=; b=uPqeC6hHWE8TWsMBh/VvGyThdTBTW8soWdW01DSZTA6O5f4s1nSzdsgDSCBGTWeFCm TcmMV1LjzLN4eSyLACl+eb9cOLsoM5JVJ3LRBqGE8/HFoEIyXIQqX25G84bW2ZKig/qE +UpaNhD8mEbt3Dve7jgGDFUg1cqVavX3pjlapc9mruks9R2S5scfmnxUvvtAE6VkJxYm Va/Am9Y9k+lQuYk/4FUYS7vvt2EJ1rLyPbDBySrvFPHxX7ptX8UOxziQNI4Q4omm88yI MWo39Zf6CaeKlv9y1+fL+kZPsmou59Skqd4KsWT7HLA6pvxIlk+jWwyUB/H2RAGZVQjW SlBg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l81si30111879pfj.230.2018.11.24.19.25.59; Sat, 24 Nov 2018 19:26:14 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726786AbeKYOPZ (ORCPT + 99 others); Sun, 25 Nov 2018 09:15:25 -0500 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:37566 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbeKYOPY (ORCPT ); Sun, 25 Nov 2018 09:15:24 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id AE1F7224AE; Sat, 24 Nov 2018 22:25:17 -0500 (EST) Date: Sun, 25 Nov 2018 14:25:25 +1100 (AEDT) From: Finn Thain To: Michael Schmitz cc: Geert Uytterhoeven , Kars de Jong , Philip Blundell , Andreas Schwab , Arnd Bergmann , Stephen N Chivers , Thomas Gleixner , Daniel Lezcano , John Stultz , Linus Walleij , linux-m68k , Linux Kernel Mailing List Subject: Re: [RFC PATCH v2 09/14] m68k: hp300: Remove hp300_gettimeoffset() In-Reply-To: <36b78174-5038-a1ac-4c70-d84a34edd275@gmail.com> Message-ID: References: <36b78174-5038-a1ac-4c70-d84a34edd275@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 25 Nov 2018, Michael Schmitz wrote: > > We can benchmark gettimeofday syscalls on elgar but is that hardware > > representative of other relevant models? > > I suppose the CIA is on the main board, so running with the slower clock > speed that you'd see with a vanilla Amiga without 060 accelerator board. > Ought to be representative enough? > Not really. An accelerated CPU clock exaggerates the slowdown factor, given the fixed 0.7 MHz CIA clock. The "(ticks > jiffy_ticks / 2)" conditional won't make anything worse even if interrupt latency is already too high, so I'm inclined towards the more prudent option. This patch series is already complicated enough. In anycase, I'd prefer not to speculate about interrupt priorities or latencies when the list probably has people who know the answers. --