From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>, Nitin Gupta <ngupta@vflare.org>,
"Sergey Senozhatsky" <sergey.senozhatsky.work@gmail.com>,
Jens Axboe <axboe@kernel.dk>,
linux-block <linux-block@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>, Alasdair Kergon <agk@redhat.com>,
Mike Snitzer <snitzer@redhat.com>, dm-devel <dm-devel@redhat.com>,
Song Liu <song@kernel.org>,
linux-raid <linux-raid@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/4] mm/swap: use SECTORS_PER_PAGE_SHIFT to clean up code
Date: Wed, 6 May 2020 17:16:04 +0800 [thread overview]
Message-ID: <8fefbfb2-1100-fab2-0383-e57343dc44f5@huawei.com> (raw)
In-Reply-To: <bddd596b-2e8e-42aa-70cc-41583b15c548@huawei.com>
On 2020/5/6 11:47, Leizhen (ThunderTown) wrote:
>
>
> On 2020/5/6 9:33, Leizhen (ThunderTown) wrote:
>>
>>
>> On 2020/5/6 1:25, Matthew Wilcox wrote:
>>> On Tue, May 05, 2020 at 07:55:41PM +0800, Zhen Lei wrote:
>>>> +++ b/mm/swapfile.c
>>>> @@ -177,8 +177,8 @@ static int discard_swap(struct swap_info_struct *si)
>>>>
>>>> /* Do not discard the swap header page! */
>>>> se = first_se(si);
>>>> - start_block = (se->start_block + 1) << (PAGE_SHIFT - 9);
>>>> - nr_blocks = ((sector_t)se->nr_pages - 1) << (PAGE_SHIFT - 9);
>>>> + start_block = (se->start_block + 1) << SECTORS_PER_PAGE_SHIFT;
>>>> + nr_blocks = ((sector_t)se->nr_pages - 1) << SECTORS_PER_PAGE_SHIFT;
>>>
>>> Thinking about this some more, wouldn't this look better?
>>>
>>> start_block = page_sectors(se->start_block + 1);
>>> nr_block = page_sectors(se->nr_pages - 1);
>>>
>>
>> OK,That's fine, it's clearer. And in this way, there won't be more than 80 columns.
>
> Should we rename "page_sectors" to "page_to_sectors"? Because we may need to define
> "sectors_to_page" also.
Change the "sectors_to_page" to "sectors_to_npage", npage means "number of pages"
or "page number". To distinguish the use case of "pfn_to_page()" etc. The latter
returns the pointer of "struct page".
>
>>
>>>
>>> .
>>>
next prev parent reply other threads:[~2020-05-06 9:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 11:55 [PATCH 0/4] eliminate SECTOR related magic numbers and duplicated conversions Zhen Lei
2020-05-05 11:55 ` [PATCH 1/4] block: Move SECTORS_PER_PAGE and SECTORS_PER_PAGE_SHIFT definitions into <linux/blkdev.h> Zhen Lei
2020-05-05 12:10 ` Matthew Wilcox
2020-05-06 4:06 ` Leizhen (ThunderTown)
2020-05-05 11:55 ` [PATCH 2/4] mm/swap: use SECTORS_PER_PAGE_SHIFT to clean up code Zhen Lei
2020-05-05 17:25 ` Matthew Wilcox
2020-05-06 1:33 ` Leizhen (ThunderTown)
2020-05-06 3:47 ` Leizhen (ThunderTown)
2020-05-06 9:16 ` Leizhen (ThunderTown) [this message]
2020-05-05 11:55 ` [PATCH 3/4] block: use SECTORS_PER_PAGE_SHIFT and SECTORS_PER_PAGE " Zhen Lei
2020-05-05 11:55 ` [PATCH 4/4] mtd: eliminate SECTOR related magic numbers Zhen Lei
2020-05-05 17:32 ` [PATCH 0/4] eliminate SECTOR related magic numbers and duplicated conversions antlists
2020-05-05 18:01 ` Matthew Wilcox
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