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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 38C90C32793 for ; Wed, 18 Jan 2023 21:34:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=b4C32lNz+rXUJZcrWcbjqxOWm8wrgPqRph2wAnjr2pU=; b=ZxM8oKDHxrXAsP YSJqxP3VLB8LGpejuF/7zBzwRZ1ynfs5BA020dB5JZ03mEHznTv+e6JXof9UH1BKOpHLXmjUgd44S ihjGErGnmuutxFQnKLeaDm8H19Ds5m9L1tOAojG7Tl+KM8JQcL3j/qxp9Xxe5gpa9jVAuyI5IPwlx AEz3iTtaaYGQSCwdrE5RGEAvxajdAXmf3oefxpYMH7MWCjGKUPYXN4ys9cqx0Opx3c7Pf2hv9ur4Y Mfamc2Lsku7TOyxMQ3kOUubHIdKS5SibvMnv3I+u+KkaFXdVv2ScMjj+dwiCeljjn4HcWM9uZ7Gjk TQy/g1GK1643smwRf0Ug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pIG42-002kYD-C4; Wed, 18 Jan 2023 21:33:46 +0000 Received: from smtp-out2.suse.de ([195.135.220.29]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pIG3z-002kWH-AC for linux-arm-kernel@lists.infradead.org; Wed, 18 Jan 2023 21:33:44 +0000 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-out2.suse.de (Postfix) with ESMTPS id 43D8D5C373; Wed, 18 Jan 2023 21:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1674077620; 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=7pZDwwkHXBi6TQs0bTATnlfLJxHePp59pNH6+hjByaY=; b=aqxWcXoZK36abrfVw7/RkaFoV9G5OwXVTbqZF7541hZRkh7wmcDUyaoUWMfXpa+rggoIxC dRlAnEppanHYrid8nc5falTWzW0Gs2cXsJVfhMTekptUZAvCgqM51Iw8aO90Z6AjGMVYGw DhRk/TYvEFKgz8v3Mm2mvdGScingIXA= 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 1A054139D2; Wed, 18 Jan 2023 21:33:40 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ByrZBbRlyGN5OgAAMHmgww (envelope-from ); Wed, 18 Jan 2023 21:33:40 +0000 Date: Wed, 18 Jan 2023 22:33:39 +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-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230118_133343_512611_5770DEFE X-CRM114-Status: GOOD ( 16.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed 18-01-23 10:09:29, Suren Baghdasaryan wrote: > On Wed, Jan 18, 2023 at 1:23 AM Michal Hocko wrote: > > > > On Tue 17-01-23 18:01:01, Suren Baghdasaryan wrote: > > > On Tue, Jan 17, 2023 at 7:16 AM Michal Hocko wrote: > > > > > > > > On Mon 09-01-23 12:53:12, Suren Baghdasaryan wrote: > > > > > Move VMA flag modification (which now implies VMA locking) before > > > > > anon_vma_lock_write to match the locking order of page fault handler. > > > > > > > > Does this changelog assumes per vma locking in the #PF? > > > > > > Hmm, you are right. Page fault handlers do not use per-vma locks yet > > > but the changelog already talks about that. Maybe I should change it > > > to simply: > > > ``` > > > 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 .... > > because vma_adjust_trans_huge() modifies the VMA and such > modifications should be done under VMA write-lock protection. 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? -- Michal Hocko SUSE Labs _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel