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;
Subject: Re: [PATCH 1/2] mm: swap: make page_evictable() inline
To:     Matthew Wilcox <willy@infradead.org>
Cc:     shakeelb@google.com, vbabka@suse.cz, akpm@linux-foundation.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <1584124476-76534-1-git-send-email-yang.shi@linux.alibaba.com>
 <20200314160157.GR22433@bombadil.infradead.org>
From:   Yang Shi <yang.shi@linux.alibaba.com>
Message-ID: <245aab40-ea54-eadc-ca9e-e85ef78b7cc7@linux.alibaba.com>
Date:   Mon, 16 Mar 2020 09:36:47 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0)
 Gecko/20100101 Thunderbird/52.7.0
MIME-Version: 1.0
In-Reply-To: <20200314160157.GR22433@bombadil.infradead.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 3/14/20 9:01 AM, Matthew Wilcox wrote:
> On Sat, Mar 14, 2020 at 02:34:35AM +0800, Yang Shi wrote:
>> -extern int page_evictable(struct page *page);
>> +/*
> This seems to be in kernel-doc format already; could you add the extra
> '*' so it is added to the fine documentation?

Yes, sure.

>
>> + * page_evictable - test whether a page is evictable
>> + * @page: the page to test
>> + *
>> + * Test whether page is evictable--i.e., should be placed on active/inactive
>> + * lists vs unevictable list.
>> + *
>> + * Reasons page might not be evictable:
>> + * (1) page's mapping marked unevictable
>> + * (2) page is part of an mlocked VMA
>> + *
>> + */
>> +static inline int page_evictable(struct page *page)
>> +{
>> +	int ret;
>> +
>> +	/* Prevent address_space of inode and swap cache from being freed */
>> +	rcu_read_lock();
>> +	ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
>> +	rcu_read_unlock();
>> +	return ret;
>> +}
> This seems like it should return bool ... that might even lead to code
> generation improvement.

Thanks for catching this. It looks mapping_unevictable() needs to be 
converted to bool as well.