Received: by 2002:ac0:a582:0:0:0:0:0 with SMTP id m2-v6csp999620imm; Fri, 12 Oct 2018 10:01:56 -0700 (PDT) X-Google-Smtp-Source: ACcGV63acKA749NobGju9530CEYEQhjRnzW84o2QBSuTtmbplwnFUJrhdh96sm1GgMDvDKW0cqyX X-Received: by 2002:a17:902:5e3:: with SMTP id f90-v6mr6863254plf.286.1539363716056; Fri, 12 Oct 2018 10:01:56 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1539363716; cv=none; d=google.com; s=arc-20160816; b=CoxsZf7WgXpZvSlbnk5mffnjT7Qh1Bl54fmRapPpvv5GaRfS+iStFA/WJSp3GumDRF jX5zTNbNjV5yEebqHkGWp4ajSscbUpmmOZ0bE1mGH2/IImJ9mL4O/kHwD2wtLqgYM4TY 40DqIF6HvCQEoBMYKuCCxUvg80FVOzECgiRQ9ro346EwXZJTZKtkHpsTf2CCKJiUt6/I 0Pfsx9iTrIYmD7Fz6SHG/lZltqQKFZFwY+TIjRMlxVSlUp6O6WbqZu7gWUedbHQUPA6C OpnDIO0Bg0mmCdMdHEiLtOCqWAeg2USE+Bh/+kBafe0KqwBCEE1Z/E3gLndWsrfu0l2c wRag== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=CgH+iPdVNwHSqUlNUrAXzvbnWqISRLd/doJ+yElEVOE=; b=QludF+OMx3WVBJ1HFs/n2xzdE7suA4NwTD20P4bg1eBrokB3kg8dt5HQuuRUnJ+L8v IUCRIbf4RG2I9LGDroRlJsCNS8PoVtN28m/C2fGymor7uhqBXSl6DAN3GfA3nJVKcmvV 06erPyhR/qKwh+Q68J8Y2Gp9siwqSeymFr7M4zjRJ02Jqk0hmr5/vfsFCjyZuCiE9uOu ZAcCzSHOu9UOzRG4XUrpijCdoAOLup3HXv9JgTUJl7UtFvGkmcpWsRUuc3LIdWkoIEd/ htqFA7P/OrK+13WsyttJo5rxS6yL6zHSS58i+UycA6g32A+Hm6em8YX9AEObKIM1XRQe l9iA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id v4-v6si1649551plp.247.2018.10.12.10.01.41; Fri, 12 Oct 2018 10:01:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727583AbeJMAe2 (ORCPT + 99 others); Fri, 12 Oct 2018 20:34:28 -0400 Received: from mga12.intel.com ([192.55.52.136]:45207 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbeJMAe2 (ORCPT ); Fri, 12 Oct 2018 20:34:28 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Oct 2018 10:01:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,373,1534834800"; d="scan'208";a="240854279" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga004.jf.intel.com with ESMTP; 12 Oct 2018 10:01:02 -0700 Date: Fri, 12 Oct 2018 10:58:04 -0600 From: Keith Busch To: Dan Williams Cc: "Kirill A. Shutemov" , Linux MM , Linux Kernel Mailing List , "Kirill A. Shutemov" , Dave Hansen , Andrew Morton Subject: Re: [PATCHv2] mm/gup: Cache dev_pagemap while pinning pages Message-ID: <20181012165803.GB15490@localhost.localdomain> References: <20181011175542.13045-1-keith.busch@intel.com> <20181012110020.pu5oanl6tnz4mibr@kshutemo-mobl1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 12, 2018 at 09:58:18AM -0700, Dan Williams wrote: > On Fri, Oct 12, 2018 at 4:00 AM Kirill A. Shutemov wrote: > [..] > > > Does this have defined behavior? I would feel better with " = { 0 }" > > > to be explicit. > > > > Well, it's not allowed by the standart, but GCC allows this. > > You can see a warning with -pedantic. > > > > We use empty-list initializers a lot in the kernel: > > $ git grep 'struct .*= {};' | wc -l > > 997 > > > > It should be fine. > > Ah, ok. I would still say we should be consistent between the init > syntax for 'ctx' in follow_page() and __get_user_pages(), and why not > go with '= { 0 }', one less unnecessary gcc'ism. No problem, I'll make that happen and copy your reviews/acks into the next patch.