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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 274BAC433FE for ; Wed, 20 Oct 2021 15:13:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1240161354 for ; Wed, 20 Oct 2021 15:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230331AbhJTPPU (ORCPT ); Wed, 20 Oct 2021 11:15:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:47190 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229702AbhJTPPT (ORCPT ); Wed, 20 Oct 2021 11:15:19 -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 5155361359; Wed, 20 Oct 2021 15:13:03 +0000 (UTC) Date: Wed, 20 Oct 2021 11:13:01 -0400 From: Steven Rostedt To: Kalesh Singh Cc: Suren Baghdasaryan , Hridya Valsaraju , Namhyung Kim , "Cc: Android Kernel" , Jonathan Corbet , Ingo Molnar , Shuah Khan , Masami Hiramatsu , Tom Zanussi , "open list:DOCUMENTATION" , LKML , "open list:KERNEL SELFTEST FRAMEWORK" Subject: Re: [PATCH v2 2/5] tracing: Add division and multiplication support for hist triggers Message-ID: <20211020111301.0032a43d@gandalf.local.home> In-Reply-To: References: <20211020013153.4106001-1-kaleshsingh@google.com> <20211020013153.4106001-3-kaleshsingh@google.com> <20211019222756.1fde436b@gandalf.local.home> 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-kernel@vger.kernel.org On Wed, 20 Oct 2021 07:54:59 -0700 Kalesh Singh wrote: > Is it worth adding something like this for the multiplication case as well? No, multiplication is a pretty fast operation, and the added branches to test would cause more overhead than what you would save. But, division is a very slow operation, and I believe that even with the extra branches it would still help. If we do this, it should be a separate patch anyway, where we can actual do measurements to see if there was an improvement, and revert if not. -- Steve