Re: [PATCH v3] selftests/mincore: get readahead size for check_file_mmap()

From: JeffleXu <jefflexu@linux.alibaba.com>
To: "Ricardo Cañuelo" <ricardo.canuelo@collabora.com>, shuah@kernel.org
Cc: linux-kselftest@vger.kernel.org, James Wang <jnwang@linux.alibaba.com>
Subject: Re: [PATCH v3] selftests/mincore: get readahead size for check_file_mmap()
Date: Wed, 14 Apr 2021 17:17:33 +0800	[thread overview]
Message-ID: <bb013423-f9b7-6fcb-944b-fb7a9b27dc4b@linux.alibaba.com> (raw)
In-Reply-To: <a582e59cdca782125929a88318eeebd24c7fda8f.camel@collabora.com>

On 4/12/21 3:15 PM, Ricardo Cañuelo wrote:
> Hi Jeffle,
> 
> Thanks for the patch.
> 
> On Mon, 2021-04-12 at 11:46 +0800, Jeffle Xu wrote:
>> -	i = FILE_SIZE / 2 / page_size + 1;
>> +	i = file_size / 2 / page_size + 1;
>>  	while (i < vec_size && vec[i]) {
>>  		ra_pages++;
>>  		i++;
> 
> One minor nit: now that you know the readahead size exactly, this could check
> that only the readahead window has been loaded and that anything beyond that is
> still not populated.

Thanks for reviewing. Yes it is. I can add this if the readahead
algorithm on this issue (touching the first page) is relatively stable,
since the readahead algorithm is not a ABI. Though selftest itself is
closely coupled with kernel.

> 
> Acked-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com>
> 

-- 
Thanks,
Jeffle