Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Subject: Re: [PATCH 03/16] mm: remove obsolete macro NR_PCP_ORDER_MASK
To:     Matthew Wilcox <willy@infradead.org>
CC:     <akpm@linux-foundation.org>, <david@redhat.com>,
        <osalvador@suse.de>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>
References: <20220909092451.24883-1-linmiaohe@huawei.com>
 <20220909092451.24883-4-linmiaohe@huawei.com>
 <YxuV94OgEF5ZQrMv@casper.infradead.org>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <075c234a-87bc-b479-366d-6bfc2731b3d5@huawei.com>
Date:   Tue, 13 Sep 2022 11:14:02 +0800
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101
 Thunderbird/78.6.0
MIME-Version: 1.0
In-Reply-To: <YxuV94OgEF5ZQrMv@casper.infradead.org>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2022/9/10 3:37, Matthew Wilcox wrote:
> On Fri, Sep 09, 2022 at 05:24:38PM +0800, Miaohe Lin wrote:
>> Since commit 8b10b465d0e1 ("mm/page_alloc: free pages in a single pass
>> during bulk free"), it's not used anymore. Remove it.
> 
> Yes, but this patch needs to go further.  The comment is no longer true
> (after the patch you mention), so need to also delete these lines:
> 
> -/*
> - * Shift to encode migratetype and order in the same integer, with order
> - * in the least significant bits.
> - */
> -#define NR_PCP_ORDER_WIDTH 8
> 
> and the line:
> -                BUILD_BUG_ON(MAX_ORDER >= (1<<NR_PCP_ORDER_WIDTH));
> 

Agree. Many thanks for pointing this out. Will do it in next version.

Thanks,
Miaohe Lin

> 
> .
>