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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E40A4C004D4 for ; Thu, 19 Jan 2023 09:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230074AbjASJbY (ORCPT ); Thu, 19 Jan 2023 04:31:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229958AbjASJbO (ORCPT ); Thu, 19 Jan 2023 04:31:14 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5F085A825 for ; Thu, 19 Jan 2023 01:31:12 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 529F637BC3; Thu, 19 Jan 2023 09:31:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1674120671; h=from:from:reply-to: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=FBT6wzhK2UunnASnPSdx/iqihHXc3wFh1VVgMsb6VKA=; b=tNshMnGxdSbA+I2e0XZ7irNDU1P9ofyO06zaZeOGrIRUrTbu32JIjVEkX2015Uqk8LTtr3 4taFAjtwB8ddwicGYKdsvkCHowFdQKOrHjraZNi/52dFMBTwO9hEtyBFtFxDlEnRjQ/zsL d5ne5VEjHi2FDliNndYnS/tZzKOO1N0= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1F421134F5; Thu, 19 Jan 2023 09:31:11 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 5vcgB98NyWMVfQAAMHmgww (envelope-from ); Thu, 19 Jan 2023 09:31:11 +0000 Date: Thu, 19 Jan 2023 10:31:10 +0100 From: Michal Hocko To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, michel@lespinasse.org, jglisse@google.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH 17/41] mm/mmap: move VMA locking before anon_vma_lock_write call Message-ID: References: <20230109205336.3665937-1-surenb@google.com> <20230109205336.3665937-18-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 18-01-23 13:48:13, Suren Baghdasaryan wrote: > On Wed, Jan 18, 2023 at 1:33 PM Michal Hocko wrote: [...] > > So it will become: > > Move VMA flag modification (which now implies VMA locking) before > > vma_adjust_trans_huge() to ensure the modifications are done after VMA > > has been locked. Because vma_adjust_trans_huge() modifies the VMA and such > > modifications should be done under VMA write-lock protection. > > > > which is effectivelly saying > > vma_adjust_trans_huge() modifies the VMA and such modifications should > > be done under VMA write-lock protection so move VMA flag modifications > > before so all of them are covered by the same write protection. > > > > right? > > Yes, and the wording in the latter version is simpler to understand > IMO, so I would like to adopt it. Do you agree? of course. -- Michal Hocko SUSE Labs