From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Pranith Kumar <bobby.prani@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>, Rik van Riel <riel@surriel.com>,
Harry Yoo <harry@kernel.org>, Jann Horn <jannh@google.com>,
Lance Yang <lance.yang@linux.dev>,
Richard Cochran <richardcochran@gmail.com>,
"open list:MEMORY MANAGEMENT - CORE" <linux-mm@kvack.org>,
open list <linux-kernel@vger.kernel.org>,
"open list:PTP HARDWARE CLOCK SUPPORT:Keyword:(?:b|_)ptp(?:b|_)"
<netdev@vger.kernel.org>
Subject: Re: [RFC PATCH] mm/rmap: use release ordering for small-folio mapcount removal
Date: Wed, 4 Nov 2026 14:37:39 +0100 [thread overview]
Message-ID: <287698ab-76dc-4aee-8e6c-db1f5d18974c@kernel.org> (raw)
In-Reply-To: <CAJhHMCCu8ehOU37_4UpExNO3U8YPygjnht+2S+axkxTwY8bx2w@mail.gmail.com>
On 11/4/26 10:46, Pranith Kumar wrote:
> Hi David,
>
> Thank you for looking at the patch.
>
> On Wed, Nov 4, 2026 at 1:16 AM David Hildenbrand (Arm) <david@kernel.org> wrote:
>>
>>
>>> In an arm64 page map/unmap microbenchmark with 20,480 minor
>>> faults, simulated cycles fell by 1.54%.
>>
>> Thanks for the patch.
>>
>> While I see value, I am not convinced this is the right time for this
>> micro-optimization while we are busy with other things.
>>
>> This needs a better evaluation: 1.54% in a micro-benchmark without knowing the
>> stddev isn't particularly helpful.
>>
>
> This result is from a deterministic simulation, hence no stddev.
Ah, I'd assume even a deterministic simulator would have some variance due to
preemption, TLB flushes etc.
But the bigger question is: which arm64 variant is simulated? I'd assume it
might vary heavily no?
--
Cheers,
David
next prev parent reply other threads:[~2026-11-04 13:37 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-04 1:31 [RFC PATCH] mm/rmap: use release ordering for small-folio mapcount removal Pranith Kumar
2026-11-04 9:16 ` David Hildenbrand (Arm)
2026-11-04 9:46 ` Pranith Kumar
2026-11-04 13:37 ` David Hildenbrand (Arm) [this message]
2026-11-04 13:55 ` Lorenzo Stoakes (ARM)
2026-11-04 16:51 ` Pranith Kumar
2026-11-04 17:08 ` Pedro Falcato
2026-11-04 17:15 ` Lorenzo Stoakes (ARM)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=287698ab-76dc-4aee-8e6c-db1f5d18974c@kernel.org \
--to=david@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=bobby.prani@gmail.com \
--cc=harry@kernel.org \
--cc=jannh@google.com \
--cc=lance.yang@linux.dev \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ljs@kernel.org \
--cc=mhocko@suse.com \
--cc=netdev@vger.kernel.org \
--cc=richardcochran@gmail.com \
--cc=riel@surriel.com \
--cc=rppt@kernel.org \
--cc=surenb@google.com \
--cc=vbabka@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox