From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Luke Yang <luyang@redhat.com>, dev.jain@arm.com
Cc: jhladky@redhat.com, akpm@linux-foundation.org,
Liam.Howlett@oracle.com, willy@infradead.org, surenb@google.com,
vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [REGRESSION] mm/mprotect: 2x+ slowdown for >=400KiB regions since PTE batching (cac1db8c3aad)
Date: Fri, 13 Feb 2026 16:47:29 +0100 [thread overview]
Message-ID: <c450ee86-4c34-449d-b144-6b4dcb996998@kernel.org> (raw)
In-Reply-To: <aY8-XuFZ7zCvXulB@luyang-thinkpadp1gen7.toromso.csb>
On 2/13/26 16:08, Luke Yang wrote:
> Hello,
Hi!
>
> we have bisected a significant mprotect() performance regression in
> 6.17-rc1 to:
>
> cac1db8c3aad ("mm: optimize mprotect() by PTE batching")
>
> The regression becomes clearly visible starting around 400 KiB region
> sizes and above. It is also still present in the latest 6.19 kernel.
>
Micro-benchmark results are nice. But what is the real word impact? IOW,
why should we care?
--
Cheers,
David
next prev parent reply other threads:[~2026-02-13 15:47 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-13 15:08 Luke Yang
2026-02-13 15:47 ` David Hildenbrand (Arm) [this message]
2026-02-13 16:24 ` Pedro Falcato
2026-02-13 17:16 ` Suren Baghdasaryan
2026-02-13 17:26 ` David Hildenbrand (Arm)
2026-02-16 10:12 ` Dev Jain
2026-02-16 14:56 ` Pedro Falcato
2026-02-17 17:43 ` Luke Yang
2026-02-17 18:08 ` Pedro Falcato
2026-02-18 5:01 ` Dev Jain
2026-02-18 10:06 ` Pedro Falcato
2026-02-18 10:38 ` Dev Jain
2026-02-18 10:46 ` David Hildenbrand (Arm)
2026-02-18 11:58 ` Pedro Falcato
2026-02-18 12:24 ` David Hildenbrand (Arm)
2026-02-19 12:15 ` Pedro Falcato
2026-02-19 13:02 ` David Hildenbrand (Arm)
2026-02-19 15:00 ` Pedro Falcato
2026-02-19 15:29 ` David Hildenbrand (Arm)
2026-02-20 4:12 ` Dev Jain
2026-02-18 11:52 ` Pedro Falcato
2026-02-18 4:50 ` Dev Jain
2026-02-18 13:29 ` David Hildenbrand (Arm)
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