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=-16.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C9F0AC433DB for ; Fri, 12 Feb 2021 14:20:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 951DB64DF0 for ; Fri, 12 Feb 2021 14:20:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231768AbhBLOTg (ORCPT ); Fri, 12 Feb 2021 09:19:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:44646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231197AbhBLOTA (ORCPT ); Fri, 12 Feb 2021 09:19:00 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 600B664DF0; Fri, 12 Feb 2021 14:18:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613139499; bh=IrzkKovhWTgaZbrcMe840lSYJH/ANV2GqSQ7EtYOXa8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OnYzn5xPd4hkgplyeplliedG++v+FtIh/YOZshc+s4AMkdGGA/WafEadyJtVnSrmT RpGWHMYZUwSVEocXEdf2wUyy9C45T6QDQpKH2uiJgGkixJLgQ3uqAHFhFvu999Vuok E1LXL/TSf/Vw7sgIQdLCeDrfgJrdjcDao+yd19ls+tzev/01CLWcm+BSwArDlPW2f6 kNuocseZrTuRTtzEQwCGw/XnCeg+J1/KLgEii4aDgDCom7yaNr+P6XuUMHBLX8Tske IulxZMtAf7oe8YEGtyw2+s/sJMv35jAaZhp+M8uf7CzT7yFwTlLI421FBRgYJXw1Ry JCQr+EAFzOa+g== Date: Fri, 12 Feb 2021 15:18:17 +0100 From: Frederic Weisbecker To: Marcelo Tosatti Cc: Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [patch 2/3] nohz: change signal tick dependency to wakeup CPUs of member tasks Message-ID: <20210212141817.GA94816@lothringen> References: <20210128202134.608115362@fuller.cnet> <20210128202235.849263653@fuller.cnet> <20210212122521.GA90839@lothringen> <20210212140041.GA182392@fuller.cnet> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210212140041.GA182392@fuller.cnet> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 12, 2021 at 11:00:41AM -0300, Marcelo Tosatti wrote: > On Fri, Feb 12, 2021 at 01:25:21PM +0100, Frederic Weisbecker wrote: > > On Thu, Jan 28, 2021 at 05:21:36PM -0300, Marcelo Tosatti wrote: > > > Rather than waking up all nohz_full CPUs on the system, only wakeup > > > the target CPUs of member threads of the signal. > > > > > > Reduces interruptions to nohz_full CPUs. > > > > > > Signed-off-by: Marcelo Tosatti > > > > > > Index: linux-2.6/kernel/time/tick-sched.c > > > =================================================================== > > > --- linux-2.6.orig/kernel/time/tick-sched.c > > > +++ linux-2.6/kernel/time/tick-sched.c > > > @@ -444,9 +444,20 @@ EXPORT_SYMBOL_GPL(tick_nohz_dep_clear_ta > > > * Set a per-taskgroup tick dependency. Posix CPU timers need this in order to elapse > > > * per process timers. > > > */ > > > -void tick_nohz_dep_set_signal(struct signal_struct *sig, enum tick_dep_bits > > > bit) > > > > Why not keeping the signal struct as a parameter? > > > > Thanks. > > All callers use "struct signal_struct *sig = tsk->signal" as > signal parameter anyway... Sure, but that makes more sense with the function role and name. > > Can change parameters to (task, signal, bit) if you prefer. That's ok I can do it, just wanted to make sure I wasn't missing a reason behind it. Thanks!