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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 8BE75C433E1 for ; Fri, 14 Aug 2020 15:26:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2846620885 for ; Fri, 14 Aug 2020 15:26:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="IIINUl+l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2846620885 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 865666B0003; Fri, 14 Aug 2020 11:26:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7C8186B0005; Fri, 14 Aug 2020 11:26:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6B63A6B0006; Fri, 14 Aug 2020 11:26:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 4FFF26B0003 for ; Fri, 14 Aug 2020 11:26:26 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id EF858180AD806 for ; Fri, 14 Aug 2020 15:26:25 +0000 (UTC) X-FDA: 77149550730.26.color60_4107a0926ffd Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id AC1A51804B66B for ; Fri, 14 Aug 2020 15:26:25 +0000 (UTC) X-HE-Tag: color60_4107a0926ffd X-Filterd-Recvd-Size: 3121 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Fri, 14 Aug 2020 15:26:25 +0000 (UTC) Received: from paulmck-ThinkPad-P72.home (unknown [50.45.173.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02285207DA; Fri, 14 Aug 2020 15:26:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597418784; bh=BuFd0GUohYMykV0bEdLt1waKCKM21ZGzCtbhCO68IFc=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=IIINUl+lN73fm93kQbcZAXjSlQanUn+3mjuNuD3Nidj6TRiHH1x8JytdH4XNdcU58 9vtGYsGEm0hgOvf4QSYePNsgOTrf5uahsMt09h8BEg99lleRxbDlvyFEdc/ZArMpHw ShSpemX1MWdH1Tp9ugrVarn7gsSnCw5beyosMS8U= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id CDEEE3522A0E; Fri, 14 Aug 2020 08:26:23 -0700 (PDT) Date: Fri, 14 Aug 2020 08:26:23 -0700 From: "Paul E. McKenney" To: peterz@infradead.org Cc: Thomas Gleixner , 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: <20200814152623.GN4295@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <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> <20200814102306.GK35926@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200814102306.GK35926@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.9.4 (2018-02-28) X-Rspamd-Queue-Id: AC1A51804B66B X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 14, 2020 at 12:23:06PM +0200, peterz@infradead.org wrote: > 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. The problem with that is common code along with the tendency of people to just use the one that "works everywhere". Thanx, Paul