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=-4.1 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 CC86FC433E8 for ; Thu, 16 Jul 2020 14:25:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A664A20825 for ; Thu, 16 Jul 2020 14:25:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="l3ZLmTNV"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="dBf+uBus" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729091AbgGPOZn (ORCPT ); Thu, 16 Jul 2020 10:25:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729066AbgGPOZl (ORCPT ); Thu, 16 Jul 2020 10:25:41 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BEE9C08C5C0; Thu, 16 Jul 2020 07:25:40 -0700 (PDT) Date: Thu, 16 Jul 2020 16:25:37 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1594909539; 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=R8pGaheYTYoGZYv5r4THVryy54oNNrDJrmVoeuGswsI=; b=l3ZLmTNV4qh6x04NTEwynyxGe7l8THGdxCYUWxLqXXP3wcyXtQ0ai34niwircMYYF8zjym n26JbEiSjL3/8CT7Px7Tonm9BjWdTLBn70gx4SBN6cgOcEznP23+k8JJIdqC6xIkaRh1Bt 2/ieXp4QNjWFHe/u+SyV4++EA3CuYpsGLHE6DbSYExAKs55OA0AiZrCywdXLNlcFLfjes+ r/xohezp/WpjDi0iW/B9oeMSljCXI2g0tpR41EXvkI4vKKKadOjmyjiFJWRWJTbbI3ITAV KaoDAygyzwwTYwYRdqWyU5fuHmLBS0WmvaD2BZYbT8MEAALFrE4a6h8lL7AgBg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1594909539; 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=R8pGaheYTYoGZYv5r4THVryy54oNNrDJrmVoeuGswsI=; b=dBf+uBusIFT/L0neyYIR02FQW3BLM6sIHJtxziWYRogPfi6O6X69EPZn6QtTBtz2wgubmE GZkc3klFzBky5fCA== From: Sebastian Andrzej Siewior To: Uladzislau Rezki Cc: Joel Fernandes , LKML , RCU , linux-mm , "Paul E . McKenney" , Andrew Morton , "Theodore Y . Ts'o" , Matthew Wilcox , Oleksiy Avramchenko Subject: Re: [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator Message-ID: <20200716142537.ecp4icsq7kg6qhdx@linutronix.de> References: <20200715183537.4010-1-urezki@gmail.com> <20200715185628.7b4k3o5efp4gnbla@linutronix.de> <20200716091913.GA28595@pc636> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200716091913.GA28595@pc636> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-07-16 11:19:13 [+0200], Uladzislau Rezki wrote: > Sebastian, could you please confirm that if that patch that is in > question fixes it? > > It would be appreciated! So that preempt disable should in terms any warnings. However I don't think that it is strictly needed and from scheduling point of view you forbid a CPU migration which might be good otherwise. Also if interrupts and everything is enabled then someone else might invoke kfree_rcu() from BH context for instance. Sebastian