From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Matthew Wilcox <willy@infradead.org>, xu.xin16@zte.com.cn
Cc: akpm@linux-foundation.org, chengming.zhou@linux.dev,
hughd@google.com, wang.yaxin@zte.com.cn, yang.yang29@zte.com.cn,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: ksm: initialize rmap values directly and make them const
Date: Fri, 6 Feb 2026 19:09:56 +0100 [thread overview]
Message-ID: <3192eca4-1c90-44ed-8386-bf635db357c4@kernel.org> (raw)
In-Reply-To: <5a1cf097-5ab4-41d1-a707-a709de6210cf@kernel.org>
On 2/6/26 18:34, David Hildenbrand (Arm) wrote:
> On 2/6/26 16:29, Matthew Wilcox wrote:
>> On Fri, Feb 06, 2026 at 03:22:54PM +0800, xu.xin16@zte.com.cn wrote:
>>> make them const to make code more robust. Besides, since KSM folios
>>> are always
>>> order-0, so folio_nr_pages(KSM folio) is always 1, so the line:
>>>
>>> "pgoff_end = pgoff_start + folio_nr_pages(folio) - 1;"
>>>
>>> becomes directly:
>>>
>>> "pgoff_end = pgoff_start;"
>>
>> How do you know KSM folios will always be order 0? I don't. NAK this
>> change.
>
> Once that changes we can revisit. ACK from me stands.
And just to elaborate a bit: I don't see support for > 0 happening any
time soon, and it will require significant changes that I am not even
sure we would want to maintain upstream :)
--
Cheers,
David
next prev parent reply other threads:[~2026-02-06 18:10 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-06 7:22 xu.xin16
2026-02-06 8:18 ` David Hildenbrand (Arm)
2026-02-06 8:38 ` xu.xin16
2026-02-06 8:46 ` David Hildenbrand (Arm)
2026-02-06 15:39 ` Andrew Morton
2026-02-06 15:29 ` Matthew Wilcox
2026-02-06 17:34 ` David Hildenbrand (Arm)
2026-02-06 18:09 ` David Hildenbrand (Arm) [this message]
2026-02-06 18:49 ` Matthew Wilcox
2026-02-06 18:57 ` David Hildenbrand (Arm)
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