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 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 9990DC4338F for ; Wed, 4 Aug 2021 16:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77E2260F94 for ; Wed, 4 Aug 2021 16:22:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237194AbhHDQWt (ORCPT ); Wed, 4 Aug 2021 12:22:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236975AbhHDQWq (ORCPT ); Wed, 4 Aug 2021 12:22:46 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C91DC0613D5; Wed, 4 Aug 2021 09:22:34 -0700 (PDT) Date: Wed, 4 Aug 2021 18:22:31 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1628094152; 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=VYAu+x/wAlGvb/Mk3k0JT/DRiAXNKYQWd63guiFfZG4=; b=dsSnqlrsS+kJGLUNtVOx6VUnKY0gldGjRifRsZbHXPISJH09MPnHz3WctVMULa7tYoMvA5 Aw8dpbFZL70KCt/8aFaSmC1cRnWSst7lKyBn8Uxm1QBX3GMpyKRlMh2AvI5cShNnklVEud BAd8zHi3lPHiI/K3k052RN3J4FCy6JLvVVDT0MT+I36lC3Wo5g2QJgaEy6qtugWakCWIbu LV6GS318yt7LQIEc0Jglcpreoka/H+AB5KnwalHW2WDPzbt0ONP2YYiI9tgbL0r+mEoTgY DXa/FIJPtPSEKqrZUuMByDOxMQJLPlZuu+blzvBNA43eqrcylrkHkcp6Y91DSQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1628094152; 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=VYAu+x/wAlGvb/Mk3k0JT/DRiAXNKYQWd63guiFfZG4=; b=tvu6dZTlyWOa8Np7RFGAqI1yqmsyEgi0kwXBBq0DDkKGUX+qN8rK5Fx1BFI9e0bsXLjfHQ Ylqds5yuk40P7iCg== 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: <20210804162231.rfj5i736lqc4nsio@linutronix.de> References: <20210804104803.4nwxi74sa2vwiujd@linutronix.de> <20210804110057.chsvt7l5xpw7bo5r@linutronix.de> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210804121704.1587c41b@oasis.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-08-04 12:17:04 [-0400], Steven Rostedt wrote: > Perhaps in this situation, we could open code it to: > > if (stall_hash != -1U) { > raw_spin_unlock(&wqe->lock); > > /* On RT the spin_lock_irq() does not disable interrupts */ > if (IS_ENABLED(CONFIG_PREEMPT_RT)) > local_irq_enable(); no preemption happens here with NEED_RESCHED set. > io_wait_on_hash(wqe, stall_hash); > > if (IS_ENABLED(CONFIG_PREEMPT_RT)) > local_irq_disable(); > raw_spin_lock(&wqe->lock); > } > > Note, I haven't looked at the rest of the code to know the ripple > effect of this, but I'm just suggesting the idea. > Sebastian