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 D2125C433F5 for ; Tue, 7 Dec 2021 22:07:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242016AbhLGWLO (ORCPT ); Tue, 7 Dec 2021 17:11:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237203AbhLGWLM (ORCPT ); Tue, 7 Dec 2021 17:11:12 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F799C061574 for ; Tue, 7 Dec 2021 14:07:42 -0800 (PST) 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=p2HVXIrwF23DFq4/7NiWJ9lVGEQY74Pg2xDdCxWPG8Y=; b=LGgYXZ/qd/ovlj7hYPn79Gwyr+ Ji17rxXwSHQefPxCBGt6uKy08/w9OMnvtk3y2K87RFNxp2IA/thktCGNo8cbh1/7p9VErIYSKamj/ Mhp+zwAuitJ9RShXUeXiU+gWbHtD0LOnRVimcn61Ks5Lq5lSiWSsy4fKendTyWJA8c/w0j5gRwH8f eAx34R8MmJMjT+HfsU5JMvo9VParjfMRYSVc4ERuK5ci6gTv8Qdb31Pw1JIyjPRfVVaY+vk9Ha0gO eW/OH4lhuAq7Rb+kVDLA2oCiBVCqEhgn45d2dhMZPBAHcSSH0XmZYVbTtRZ1rnJFXif6WO6F2YY9d FrY89R7g==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1muicG-007oqq-2O; Tue, 07 Dec 2021 22:07:16 +0000 Date: Tue, 7 Dec 2021 22:07:16 +0000 From: Matthew Wilcox To: Suren Baghdasaryan Cc: akpm@linux-foundation.org, mhocko@kernel.org, mhocko@suse.com, rientjes@google.com, hannes@cmpxchg.org, guro@fb.com, riel@surriel.com, minchan@kernel.org, kirill@shutemov.name, aarcange@redhat.com, christian@brauner.io, hch@infradead.org, oleg@redhat.com, david@redhat.com, jannh@google.com, shakeelb@google.com, luto@kernel.org, christian.brauner@ubuntu.com, fweimer@redhat.com, jengelh@inai.de, timmurray@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3 1/2] mm: protect free_pgtables with mmap_lock write lock in exit_mmap Message-ID: References: <20211207215031.2251719-1-surenb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211207215031.2251719-1-surenb@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 07, 2021 at 01:50:30PM -0800, Suren Baghdasaryan wrote: > - Added a comment for vm_operations_struct::close, documenting restriction for > taking mmap_lock in the callback, per Michal Hocko and Matthew Wilcox This should be a separate patch because it stands alone, but ... > struct vm_operations_struct { > void (*open)(struct vm_area_struct * area); > + /* > + * Called with mmap_lock lock held for write from __split_vma and > + * remove_vma, therefore should never take that lock. > + */ Your whitespace indentation is weird. And it'd be nice to make this a kernel-doc comment (I know none of the others are, but that should be fixed too). And naming the functions that call it is wrong too. /** * @close: Called when the VMA is being removed from the MM. * Context: Caller holds mmap_lock. */