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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 47087C433F5 for ; Fri, 10 Sep 2021 12:45:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DBDF60E94 for ; Fri, 10 Sep 2021 12:45:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233737AbhIJMqo (ORCPT ); Fri, 10 Sep 2021 08:46:44 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:38424 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233683AbhIJMqn (ORCPT ); Fri, 10 Sep 2021 08:46:43 -0400 Date: Fri, 10 Sep 2021 14:45:30 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1631277931; 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=kYe9djVH32oIH1dMg/4UjSUuB4tMkZH3lMYm37JAmKk=; b=w+k4dlfOOv7gn5eutCAba/foctsxreNZ4ry2tb6w4PXPlKcgSDM8Ceq3VK8NSCyGDYibiw C06iw+7yUoIV/VAxyQ9ZwJ16BO+yK4vGK7yNUtuMZXv68GgvvdnllhWxWRfU1spWVvEDRK DMCwo0fJTQ+LIRdz9QmnFkWNegRvEVcFZoHhsIaw6xAtF2Kneu8BRrqRx+akpdcU3yLrl7 LkfSJ8Ec3KcUObMDk40940jM7wkl89y23Qqdn+Gdu/8VThNJ1c58cwVGKPdPCPnUsdOBgc XYxDzawY7nKXlEMM7Oz+30jpvry+c9g4ahGAh5LLo5djlDCwP4rIhgNVd/sk4Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1631277931; 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=kYe9djVH32oIH1dMg/4UjSUuB4tMkZH3lMYm37JAmKk=; b=AdsAeligySKM6SzqdjbDXCbe8QdfU3L2ILy9rWSDZPjeIoOBtuy2qnH6MlEPJT1GgufPDQ yuf71zaDqRumWfBw== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: tglx@linutronix.de, boqun.feng@gmail.com, linux-kernel@vger.kernel.org, Ingo Molnar , Juri Lelli , Steven Rostedt , Davidlohr Bueso , Will Deacon , Waiman Long , Mike Galbraith , Daniel Bristot de Oliveira Subject: Re: [PATCH 1/4] sched/wakeup: Strengthen current_save_and_set_rtlock_wait_state() Message-ID: <20210910124530.iezmxpzzhkbl6gwt@linutronix.de> References: <20210909105915.757320973@infradead.org> <20210909110203.767330253@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210909110203.767330253@infradead.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-09-09 12:59:16 [+0200], Peter Zijlstra wrote: > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -253,22 +254,24 @@ struct task_group; > */ > #define current_save_and_set_rtlock_wait_state() \ > do { \ > - lockdep_assert_irqs_disabled(); \ > - raw_spin_lock(¤t->pi_lock); \ > + unsigned long flags; /* may shadow */ \ could we haz __flags so no shadow? > + \ > + raw_spin_lock_irqsave(¤t->pi_lock, flags); \ > current->saved_state = current->__state; \ > debug_rtlock_wait_set_state(); \ > - WRITE_ONCE(current->__state, TASK_RTLOCK_WAIT); \ > - raw_spin_unlock(¤t->pi_lock); \ > + smp_store_mb(current->__state, TASK_RTLOCK_WAIT); \ > + raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \ Sebastian