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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 3A8E6C433DF for ; Fri, 14 Aug 2020 10:23:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 164E020781 for ; Fri, 14 Aug 2020 10:23:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Udj4hUqe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726787AbgHNKXV (ORCPT ); Fri, 14 Aug 2020 06:23:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726012AbgHNKXU (ORCPT ); Fri, 14 Aug 2020 06:23:20 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D5B9C061383; Fri, 14 Aug 2020 03:23:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2bzdVcEaOY9NKXRzVCZZ4sATksY3jrzQirPEzdSYgjQ=; b=Udj4hUqe3bw8kl4v/Dp54CIPsr VKWn8vvCTPIkIW3fOq5z/jLcbdNMwEZjGL5Zk0p1oqRioYu6vFdl1mTvx+aOvxkVdrNrVxJ6PDAkd 9lhbIE2yRRNy6r7Msr8RJgZw7BbyB19SveC/v/wpYEFXzKd7GyiG6BxYK4dhTK2/nE+mjbA5F57/g sceZyYLg5bsFsPVP9MWZ6WbmoIBd/EWjNYLkQOGtVdXNlm7cCrvRNTQmBeTaTkklKspqHBtfpKfTG S+ZwaZONPYo6oUM9Qd/RDf4IFlONJapXDj8ZTlmmJNrI2fbxbkyPPcJICA7q1H1a1W0QeSjRR+eZh S7Vbdeig==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k6Wrb-0003QY-DE; Fri, 14 Aug 2020 10:23:07 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5D5F030066E; Fri, 14 Aug 2020 12:23:06 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 497C22C33E600; Fri, 14 Aug 2020 12:23:06 +0200 (CEST) Date: Fri, 14 Aug 2020 12:23:06 +0200 From: peterz@infradead.org To: Thomas Gleixner Cc: "Paul E. McKenney" , Michal Hocko , Uladzislau Rezki , LKML , RCU , linux-mm@kvack.org, Andrew Morton , Vlastimil Babka , Matthew Wilcox , "Theodore Y . Ts'o" , Joel Fernandes , Sebastian Andrzej Siewior , Oleksiy Avramchenko Subject: Re: [RFC-PATCH 1/2] mm: Add __GFP_NO_LOCKS flag Message-ID: <20200814102306.GK35926@hirez.programming.kicks-ass.net> References: <20200813075027.GD9477@dhcp22.suse.cz> <20200813095840.GA25268@pc636> <874kp6llzb.fsf@nanos.tec.linutronix.de> <20200813133308.GK9477@dhcp22.suse.cz> <87sgcqty0e.fsf@nanos.tec.linutronix.de> <20200813182618.GX2674@hirez.programming.kicks-ass.net> <20200813185257.GF4295@paulmck-ThinkPad-P72> <20200813220619.GA2674@hirez.programming.kicks-ass.net> <875z9m3xo7.fsf@nanos.tec.linutronix.de> <20200814083037.GD3982@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200814083037.GD3982@worktop.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 14, 2020 at 10:30:37AM +0200, Peter Zijlstra wrote: > > > 1. Prohibit invoking allocators from raw atomic context, such > > > as when holding a raw spinlock. > > > > Clearly the simplest solution but not Pauls favourite and > > unfortunately he has a good reason. > > Which isn't actually stated anywhere I suppose ? Introduce raw_kfree_rcu() that doesn't do the allocation, and fix the few wonky callsites.