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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0EC06C3815B for ; Mon, 20 Apr 2020 19:33:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C1C5E20782 for ; Mon, 20 Apr 2020 19:33:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IODJ9iDC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C1C5E20782 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 55EAD8E0005; Mon, 20 Apr 2020 15:33:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 50F208E0003; Mon, 20 Apr 2020 15:33:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 425678E0005; Mon, 20 Apr 2020 15:33:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0207.hostedemail.com [216.40.44.207]) by kanga.kvack.org (Postfix) with ESMTP id 288888E0003 for ; Mon, 20 Apr 2020 15:33:15 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id E13AB824556B for ; Mon, 20 Apr 2020 19:33:14 +0000 (UTC) X-FDA: 76729231908.08.music35_1c540d4965f37 X-HE-Tag: music35_1c540d4965f37 X-Filterd-Recvd-Size: 2524 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Apr 2020 19:33:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=Nys6FfrXrT/gkHzZ8xBczpZW1k4deji5R46CFHQSXRI=; b=IODJ9iDC6uH9h4ewqA894kbWlj 2fuCalRawyjjvQ9m5sOYWzRepZ1K7U6sUm3IobITEqL/SRbKCAPNvCknV6JBzAlkmwmHqU7EPdT75 khpcvu48gLcAPzN+9O17TqpPeSlZ76yqoEDjcemTImGY33gHHNG8Ndp/avwUUOBJhc40Ti22EaRvG HyJfb0Zj23l/Q0K7w7FxkgiwHpdAGzsSqSK5N69HbcT15OLwErUhXftIEXNliptADHm+nOZO/6ekN CJmvacYjNQ5wkK+HoVs6LoVOgqa5iyXwiE4CgoP2cfgl5kejlL0HJVyQdmv8Fr/tLHpOmmA0Wu8ka rocxg6fA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jQcAI-0002MG-PZ; Mon, 20 Apr 2020 19:33:10 +0000 Date: Mon, 20 Apr 2020 12:33:10 -0700 From: Matthew Wilcox To: Michel Lespinasse Cc: Andrew Morton , linux-mm , LKML , Peter Zijlstra , Laurent Dufour , Vlastimil Babka , Liam Howlett , Jerome Glisse , Davidlohr Bueso , David Rientjes , Hugh Dickins , Ying Han , Jason Gunthorpe , Daniel Jordan Subject: Re: [PATCH v4 06/10] mmap locking API: convert nested write lock sites Message-ID: <20200420193310.GF5820@bombadil.infradead.org> References: <20200415004353.130248-1-walken@google.com> <20200415004353.130248-7-walken@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200415004353.130248-7-walken@google.com> 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 Tue, Apr 14, 2020 at 05:43:49PM -0700, Michel Lespinasse wrote: > @@ -47,7 +48,7 @@ static inline void activate_mm(struct mm_struct *old, struct mm_struct *new) > * when the new ->mm is used for the first time. > */ > __switch_mm(&new->context.id); > - down_write_nested(&new->mmap_sem, 1); > + mmap_write_lock_nested(new, 1); This should have already been using SINGLE_DEPTH_NESTING. 1 is uninformative.