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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 68C78C433E0 for ; Fri, 22 May 2020 14:22:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 270D9224D3 for ; Fri, 22 May 2020 14:22:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 270D9224D3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C07678000A; Fri, 22 May 2020 10:22:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BB7C380007; Fri, 22 May 2020 10:22:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ACE028000A; Fri, 22 May 2020 10:22:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) by kanga.kvack.org (Postfix) with ESMTP id 9A52180007 for ; Fri, 22 May 2020 10:22:00 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 51748181AEF23 for ; Fri, 22 May 2020 14:22:00 +0000 (UTC) X-FDA: 76844569200.24.point57_2e8bb3dad713e X-HE-Tag: point57_2e8bb3dad713e X-Filterd-Recvd-Size: 2605 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf50.hostedemail.com (Postfix) with ESMTP for ; Fri, 22 May 2020 14:21:59 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EC6FAAD12; Fri, 22 May 2020 14:22:00 +0000 (UTC) Subject: Re: [PATCH v6 12/12] mmap locking API: convert mmap_sem comments To: Andrew Morton , Michel Lespinasse Cc: linux-mm , LKML , Peter Zijlstra , Laurent Dufour , Matthew Wilcox , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan , John Hubbard References: <20200520052908.204642-1-walken@google.com> <20200520052908.204642-13-walken@google.com> <20200521102516.01dbc9fcc539baba96224c3f@linux-foundation.org> From: Vlastimil Babka Message-ID: <9858cd98-b303-beb4-82f6-52f902f98772@suse.cz> Date: Fri, 22 May 2020 16:21:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200521102516.01dbc9fcc539baba96224c3f@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 5/21/20 7:25 PM, Andrew Morton wrote: > On Thu, 21 May 2020 00:50:56 -0700 Michel Lespinasse wrote: > >> > > * Must be called holding task's alloc_lock to protect task's mems_allowed >> > > - * and mempolicy. May also be called holding the mmap_semaphore for write. >> > > + * and mempolicy. May also be called holding the mmap_lockaphore for write. >> > > */ >> > > static int mpol_set_nodemask(struct mempolicy *pol, >> > > const nodemask_t *nodes, struct nodemask_scratch *nsc) >> > >> > :) >> >> Haha, good catch ! > > aww, you're all so cruel. The world would be a better place if Linux > had lockaphores! Heh, in fact it does have them, but they are called "btrfs extent buffer locks", see (or perhaps rather not) fs/btrfs/locking.c :)