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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 BDB42C4338F for ; Wed, 4 Aug 2021 16:31:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9DAB660F0F for ; Wed, 4 Aug 2021 16:31:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237810AbhHDQbh (ORCPT ); Wed, 4 Aug 2021 12:31:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55474 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229750AbhHDQbf (ORCPT ); Wed, 4 Aug 2021 12:31:35 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84F5CC0613D5; Wed, 4 Aug 2021 09:31:22 -0700 (PDT) Date: Wed, 4 Aug 2021 18:31:19 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1628094681; 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=aOC4dsj6TxzTA0IS5KEFQan2GWU0NpOoRWb6BDoMDbM=; b=0Zjmv52JL+nNnwB3dAkRER5TBD+gcZeq3Q+YcBdo024LpS4lzLbgBrJudIKvrbTkDAmn5K zwyM+uaA//PkEnlEjGiHPA8UbDKVSn9KnfmLTc7puetq6OZ9SCa7uVgFUkHPElMWOn/TN4 fjKn8l+3+aE/n/41krCHpV1MYMDnWds5UJ7vEnlyJQRMuZ2dw49pZMywCrfYdjB6d61vej P2SJg3uXjkMS2mw2GgP021is7PkBsXTHiJBWTmuArIAwyz19so18n/2BYnoxqCiyx1726U HnalD9omt1nDxWfrwiRND1qrvdqXH6k8xL2XxvrPfRNUzP1Xp0GrOHWLrNEF0Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1628094681; 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=aOC4dsj6TxzTA0IS5KEFQan2GWU0NpOoRWb6BDoMDbM=; b=6kf3rij4FgsTg58XVH0UFPF4O9ywZPA6KUtsNRN1ie6Ok6mN+781JilT9ttPK55d7miutC UaM0LrzR1MVa04AA== From: Sebastian Andrzej Siewior To: Steven Rostedt Cc: Jens Axboe , Peter Zijlstra , Daniel Wagner , Thomas Gleixner , LKML , linux-rt-users@vger.kernel.org Subject: Re: [ANNOUNCE] v5.14-rc4-rt4 Message-ID: <20210804163119.t4c7bkpdk33byxtx@linutronix.de> References: <20210804131731.GG8057@worktop.programming.kicks-ass.net> <4f549344-1040-c677-6a6a-53e243c5f364@kernel.dk> <20210804153308.oasahcxjmcw7vivo@linutronix.de> <20210804154743.niogqvnladdkfgi2@linutronix.de> <7c946918-ae0d-6195-6a78-b019f9bc1fd3@kernel.dk> <20210804121704.1587c41b@oasis.local.home> <20210804162231.rfj5i736lqc4nsio@linutronix.de> <20210804122541.741cf858@oasis.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210804122541.741cf858@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-08-04 12:25:41 [-0400], Steven Rostedt wrote: > On Wed, 4 Aug 2021 18:22:31 +0200 > Sebastian Andrzej Siewior wrote: > > > no preemption happens here with NEED_RESCHED set. > > But if interrupts were disabled, how would NEED_RESCHED be set? As soon > as you enable interrupts, the interrupt that sets NEED_RESCHED would > trigger the preemption. CPU-local wake-ups just set NEED_RESCHED and wait for preempt_enable() to do the magic. Just because the code not perform wake_up() now does not mean it will not do so in the future. Also it is here as an example which might be copied somewhere else. > -- Steve Sebastian