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 795E6C433E1 for ; Wed, 15 Jul 2020 18:56:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52C1720656 for ; Wed, 15 Jul 2020 18:56:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="R4D+AiV2"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="BYgsGz19" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726634AbgGOS4c (ORCPT ); Wed, 15 Jul 2020 14:56:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbgGOS4b (ORCPT ); Wed, 15 Jul 2020 14:56:31 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0D78C061755; Wed, 15 Jul 2020 11:56:31 -0700 (PDT) Date: Wed, 15 Jul 2020 20:56:28 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1594839390; 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=2PN8gG1ug5BCAvCUnGhwhg5gYQ43BA/zafzatUzWINU=; b=R4D+AiV2imCWssvgqXOuVrfKHCQtMW+CVuWoK3NtD2qZklOSLot8laIhJ9mJeLlGyf0uax yzX6CyIiRxUMJ6rjtf8109vdayCECBU56t5ZlQ2nJfYq5HivepxGvBG1xJ5w5FGnL2IltR D5MSBBbDlceV8dQRmru3wnT18irOKyEi/OU/ZptBkF/uu+EpJkYE5Kae6k80rfNUnYnVwo ln41llnDzcrNIagkKDtPklwBwqXQmrYFGJMMAe5gbXuom/pxIWxHJxWObWa/kgmJdAJL/Q MRvuTDvfhWZ3B5MpEI1rrkP6y735RUNe3Io1T4u9TjYFDG9k/bs3WN86F0wAsg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1594839390; 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=2PN8gG1ug5BCAvCUnGhwhg5gYQ43BA/zafzatUzWINU=; b=BYgsGz19jrlreZ3rVkXyiR3JGReye/jbdQZdcxicBlFNJqUSI7TCoFuncbKXVcW9rG55m/ Fs4+kWRGKkBNRVBw== From: Sebastian Andrzej Siewior To: "Uladzislau Rezki (Sony)" Cc: LKML , RCU , linux-mm@kvack.org, "Paul E . McKenney" , Andrew Morton , "Theodore Y . Ts'o" , Matthew Wilcox , Joel Fernandes , Oleksiy Avramchenko Subject: Re: [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator Message-ID: <20200715185628.7b4k3o5efp4gnbla@linutronix.de> References: <20200715183537.4010-1-urezki@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200715183537.4010-1-urezki@gmail.com> Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On 2020-07-15 20:35:37 [+0200], Uladzislau Rezki (Sony) wrote: > @@ -3306,6 +3307,9 @@ kvfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_cpu *krcp, void *ptr) > if (IS_ENABLED(CONFIG_PREEMPT_RT)) > return false; > > + preempt_disable(); > + krc_this_cpu_unlock(*krcp, *flags); Now you enter memory allocator with disabled preemption. This isn't any better but we don't have a warning for this yet. What happened to the part where I asked for a spinlock_t? > + > /* > * NOTE: For one argument of kvfree_rcu() we can > * drop the lock and get the page in sleepable Sebastian