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Message-ID: <c5c2ae26-d405-4b0f-8bf6-281abcdb3239@intel.com>
Date: Fri, 19 Apr 2024 10:25:41 +0800
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v1 02/18] mm/rmap: always inline anon/file rmap
 duplication of a single PTE
To: David Hildenbrand <david@redhat.com>, <linux-kernel@vger.kernel.org>
CC: <linux-mm@kvack.org>, <linux-doc@vger.kernel.org>,
	<cgroups@vger.kernel.org>, <linux-sh@vger.kernel.org>,
	<linux-trace-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>, Andrew
 Morton <akpm@linux-foundation.org>, "Matthew Wilcox (Oracle)"
	<willy@infradead.org>, Peter Xu <peterx@redhat.com>, Ryan Roberts
	<ryan.roberts@arm.com>, Yang Shi <shy828301@gmail.com>, Zi Yan
	<ziy@nvidia.com>, Jonathan Corbet <corbet@lwn.net>, Hugh Dickins
	<hughd@google.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Rich Felker
	<dalias@libc.org>, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
	Chris Zankel <chris@zankel.net>, Max Filippov <jcmvbkbc@gmail.com>, "Muchun
 Song" <muchun.song@linux.dev>, Miaohe Lin <linmiaohe@huawei.com>, "Naoya
 Horiguchi" <naoya.horiguchi@nec.com>, Richard Chang <richardycc@google.com>
References: <20240409192301.907377-1-david@redhat.com>
 <20240409192301.907377-3-david@redhat.com>
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From: "Yin, Fengwei" <fengwei.yin@intel.com>
In-Reply-To: <20240409192301.907377-3-david@redhat.com>
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On 4/10/2024 3:22 AM, David Hildenbrand wrote:
> As we grow the code, the compiler might make stupid decisions and
> unnecessarily degrade fork() performance. Let's make sure to always inline
> functions that operate on a single PTE so the compiler will always
> optimize out the loop and avoid a function call.
> 
> This is a preparation for maintining a total mapcount for large folios.
> 
> Signed-off-by: David Hildenbrand<david@redhat.com>
The patch looks good to me. Just curious: Is this change driven by code
reviewing or performance data profiling? Thanks.


Regards
Yin, Fengwei