From: Baolin Wang <baolin.wang@linux.alibaba.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org,
riel@surriel.com, liam@infradead.org, vbabka@kernel.org,
harry@kernel.org, jannh@google.com, lance.yang@linux.dev,
kasong@tencent.com, qi.zheng@linux.dev, shakeel.butt@linux.dev,
baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com,
weixugc@google.com, mhocko@kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] mm: mglru: promote mapped executable folios after first usage
Date: Fri, 17 Jul 2026 20:58:30 +0800 [thread overview]
Message-ID: <704bbe81-a0d9-4ba6-9d3e-82efd7db4294@linux.alibaba.com> (raw)
In-Reply-To: <20260717124403.GG6843@cmpxchg.org>
On 7/17/26 8:44 PM, Johannes Weiner wrote:
> On Fri, Jul 17, 2026 at 06:05:34PM +0800, Baolin Wang wrote:
>> Classical LRU protects mapped executable file folios through commit
>> 8cab4754d24a0 ("vmscan: make mapped executable pages the first class
>> citizen") and commit c909e99364c8 ("vmscan: activate executable pages
>> after first usage"), giving executable code a better chance to stay in
>> memory, avoiding IO thrashing and improving workload performance.
>>
>> However, MGLRU's protection of mapped executable file folios is less
>> reliable. Although shrink_folio_list() checks references, the access flag
>> of mapped executable file folios may have already been checked and
>> cleared by lru_gen_look_around() or walk_mm(). Additionally,
>> folio_update_gen() or lru_gen_set_refs() only sets the 'PG_referenced'
>> flag for mapped executable file folios, which causes shrink_folio_list()
>> to ignore the first usage of these mapped executable file folios and
>> reclaim them easily.
>>
>> Follow the classical LRU's logic, promoting mapped executable file folios
>> after their first usage in folio_update_gen() and lru_gen_set_refs(),
>> giving executable code a better chance to stay in memory.
>>
>> On my 32-core Arm machine, with the memcg limit set to 2G, running
>> 'make -j32' to build kernel showed some improvement in sys time.
>>
>> base patched
>> 9248.543s 7861.579s
>>
>> While we are at it, introduce a new helper to check mapped executable
>> file folios.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>
> Both patches contained herein look good:
>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks for reviewing.
> [ Sorry ;-) Please don't mix refactoring work with functional
> changes. It's difficult to look through a sequence of diff hunks
> with more than one review narrative interleaved. ]
Ha, sure. Sorry for mixing in a helper replacement. I'll split it out
into a separate patch next time. :)
next prev parent reply other threads:[~2026-07-17 12:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-17 10:05 [PATCH v3 0/2] promote mapped executable folios after first usage for MGLRU Baolin Wang
2026-07-17 10:05 ` [PATCH v3 1/2] mm: vmscan: convert folio_referenced() to use vma_flags_t Baolin Wang
2026-07-17 12:34 ` Johannes Weiner
2026-07-17 10:05 ` [PATCH v3 2/2] mm: mglru: promote mapped executable folios after first usage Baolin Wang
2026-07-17 12:44 ` Johannes Weiner
2026-07-17 12:58 ` Baolin Wang [this message]
2026-07-17 17:27 ` [PATCH v3 0/2] promote mapped executable folios after first usage for MGLRU Axel Rasmussen
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=704bbe81-a0d9-4ba6-9d3e-82efd7db4294@linux.alibaba.com \
--to=baolin.wang@linux.alibaba.com \
--cc=akpm@linux-foundation.org \
--cc=axelrasmussen@google.com \
--cc=baohua@kernel.org \
--cc=david@kernel.org \
--cc=hannes@cmpxchg.org \
--cc=harry@kernel.org \
--cc=jannh@google.com \
--cc=kasong@tencent.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@kernel.org \
--cc=qi.zheng@linux.dev \
--cc=riel@surriel.com \
--cc=shakeel.butt@linux.dev \
--cc=vbabka@kernel.org \
--cc=weixugc@google.com \
--cc=yuanchu@google.com \
/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