Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3389903pxk;
        Mon, 28 Sep 2020 16:46:52 -0700 (PDT)
X-Google-Smtp-Source: ABdhPJyXizWjshWHYhVpXEw3+L/9VfsnHOzOaYc+q489ch7hRmizuN45R4JTbc/59ogGDKsUEQwL
X-Received: by 2002:a05:6402:1819:: with SMTP id g25mr430484edy.292.1601336811872;
        Mon, 28 Sep 2020 16:46:51 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1601336811; cv=none;
        d=google.com; s=arc-20160816;
        b=EA8yB3cG4ubUUpxUm3e08VNy8RYAzUbuHswrMZdMnNmBkQVjbuYOg/xMtX6GLINrqw
         ABYkkdbuXYMCIF4HfRv5/uYEkbWWWmuWHCaL3sEKeNbRy+qI8H7dMeQw3VL1pKRe0CiZ
         Ckfb8OPhpGDejx78cx7M3ZzQmFn2zKkWOjgKxbhm94wl4pz++0l/6iEo3zzCAb0j0S7M
         1jHKCrQWsPOyicb5z7ly3lsDK/g599e8Jafrg42horFOi0S+PQHBR1CUBAGuSy13ubDu
         4Zyc+lXkJAze0qvxCDexkHKSNrrD6bgfP2ggOwBbvE61kDodAPy9e2MpTKUjhvQbm/sT
         YSCA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816;
        h=list-id:precedence:dkim-signature:content-transfer-encoding
         :content-language:in-reply-to:mime-version:user-agent:date
         :message-id:from:references:cc:to:subject;
        bh=kXgGmngSFGVJLCne8DZRhWZR5kT4/vprhys6/EFUF2M=;
        b=0jcP1nE52Wc2fbefws8yCLMXzMjn6lpJheu+m4CyrbiPqovzD+j4HDd9NzJEyWeg4L
         +p8gV+1Hc0Ffmo36BRGzO4W7YlYPwyxDKUiWw99OwopfMagXVgV9aoD1Jt6S1PXEa/ex
         RhtP0sTqvXwuKC0/2gF1yyW3TIzWoKIZVpIjYKnkFcSCnOU18SPjX1w6/KYOJSdkc4O6
         +qNESe9Z04S2tfJBrDywPEi8I2m45DH+qlDk8/wADPM9PSzrbc5UFy/LbXii3CiVSNrM
         u5CFDsumXCqhTI5MuYp+J1ZwFVbUpGxC7nbtg3ZB7yYXYbtIjn9YmVkyimW6mo2KR53N
         QFTA==
ARC-Authentication-Results: i=1; mx.google.com;
       dkim=pass header.i=@nvidia.com header.s=n1 header.b="aUo++/WB";
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18])
        by mx.google.com with ESMTP id p13si1646511edx.248.2020.09.28.16.46.21;
        Mon, 28 Sep 2020 16:46:51 -0700 (PDT)
Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Authentication-Results: mx.google.com;
       dkim=pass header.i=@nvidia.com header.s=n1 header.b="aUo++/WB";
       spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
       dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1727048AbgI1Xk5 (ORCPT <rfc822;sbrunau@gmail.com> + 99 others);
        Mon, 28 Sep 2020 19:40:57 -0400
Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:15787 "EHLO
        hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1726064AbgI1Xk5 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Mon, 28 Sep 2020 19:40:57 -0400
Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA)
        id <B5f7261930000>; Mon, 28 Sep 2020 15:20:03 -0700
Received: from rcampbell-dev.nvidia.com (10.124.1.5) by HQMAIL107.nvidia.com
 (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 28 Sep
 2020 22:20:48 +0000
Subject: Re: [PATCH 1/2] ext4/xfs: add page refcount helper
To:     Christoph Hellwig <hch@lst.de>
CC:     <linux-mm@kvack.org>, <kvm-ppc@vger.kernel.org>,
        <nouveau@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        Dan Williams <dan.j.williams@intel.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Matthew Wilcox <willy@infradead.org>,
        Jerome Glisse <jglisse@redhat.com>,
        John Hubbard <jhubbard@nvidia.com>,
        Alistair Popple <apopple@nvidia.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Bharata B Rao <bharata@linux.ibm.com>,
        Zi Yan <ziy@nvidia.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Yang Shi <yang.shi@linux.alibaba.com>,
        Paul Mackerras <paulus@ozlabs.org>,
        Ben Skeggs <bskeggs@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>
References: <20200925204442.31348-1-rcampbell@nvidia.com>
 <20200925204442.31348-2-rcampbell@nvidia.com> <20200926063539.GA3540@lst.de>
X-Nvconfidentiality: public
From:   Ralph Campbell <rcampbell@nvidia.com>
Message-ID: <e56a1de5-6bd7-9f18-60ce-0493bcdc6413@nvidia.com>
Date:   Mon, 28 Sep 2020 15:20:48 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.2.2
MIME-Version: 1.0
In-Reply-To: <20200926063539.GA3540@lst.de>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Originating-IP: [10.124.1.5]
X-ClientProxiedBy: HQMAIL101.nvidia.com (172.20.187.10) To
 HQMAIL107.nvidia.com (172.20.187.13)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1;
        t=1601331603; bh=kXgGmngSFGVJLCne8DZRhWZR5kT4/vprhys6/EFUF2M=;
        h=Subject:To:CC:References:X-Nvconfidentiality:From:Message-ID:Date:
         User-Agent:MIME-Version:In-Reply-To:Content-Type:Content-Language:
         Content-Transfer-Encoding:X-Originating-IP:X-ClientProxiedBy;
        b=aUo++/WBuUmLpUNBybZqcSQddWcOAIgf4CiMoG8F4r7DyK/3GkcxcNtxtJXcGJ8PN
         JvprWJRK7sbeM2NyReaAn7I987qhfn6ckD/XANP2zADXzuiDLD7eThOUjsYwuwDpiz
         hu+TdV/9fyzLHRNHLAwtjvkg9n/0Jjl45ksOv1QRU8V/kTmdTC+mkEPHuWxe+ZOXOP
         oR+WkNXbdUlIq5pJYjS8ZZWazDqy3KwPhj/PeS/z9SwtdEHg89HObrdt49PKUMNTYG
         hhw6ehtOqBCJhT/J/reqmp+th5ms5Og27Zpku+FrIqrVNTP/Ay/M9FYJfcwGpEl6Qw
         HTya2AGEgwLcQ==
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


On 9/25/20 11:35 PM, Christoph Hellwig wrote:
> On Fri, Sep 25, 2020 at 01:44:41PM -0700, Ralph Campbell wrote:
>>   		error = ___wait_var_event(&page->_refcount,
>> -				atomic_read(&page->_refcount) == 1,
>> +				dax_layout_is_idle_page(page),
>>   				TASK_INTERRUPTIBLE, 0, 0,
>>   				ext4_wait_dax_page(ei));
> 
>> +++ b/fs/xfs/xfs_file.c
>> @@ -750,7 +750,7 @@ xfs_break_dax_layouts(
>>   
>>   	*retry = true;
>>   	return ___wait_var_event(&page->_refcount,
>> -			atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
>> +			dax_layout_is_idle_page(page), TASK_INTERRUPTIBLE,
>>   			0, 0, xfs_wait_dax_page(inode));
>>   }
> 
> I still think a litte helper macro would be nice here:
> 
> #define dax_wait_page(_inode, _page, _wait_cb)				\
>    	___wait_var_event(&(_page)->_refcount,				\
> 		atomic_read(&(_page)->_refcount) == 1,			\
> 		TASK_INTERRUPTIBLE, dax_layout_is_idle_page(_page),	\
> 		TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode));

OK, I'll add it in v3.