From: Lance Yang <lance.yang@linux.dev>
To: usama.arif@linux.dev
Cc: david@kernel.org, lance.yang@linux.dev,
ying.huang@linux.alibaba.com, baoquan.he@linux.dev,
willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org,
riel@surriel.com, ljs@kernel.org, shakeel.butt@linux.dev,
alex@ghiti.fr, kas@kernel.org, baohua@kernel.org,
dev.jain@arm.com, baolin.wang@linux.alibaba.com,
npache@redhat.com, linux-mm@kvack.org, akpm@linux-foundation.org,
liam@infradead.org, ryan.roberts@arm.com, chrisl@kernel.org,
vbabka@kernel.org, linux-kernel@vger.kernel.org,
nphamcs@gmail.com, shikemeng@huaweicloud.com,
kernel-team@meta.com, kasong@tencent.com, ziy@nvidia.com
Subject: Re: [v2 00/16] mm: PMD-level swap entries for anonymous THPs
Date: Sat, 13 Jun 2026 12:22:32 +0800 [thread overview]
Message-ID: <20260613042232.93691-1-lance.yang@linux.dev> (raw)
In-Reply-To: <680441bf-c878-4a00-8787-63ad8b201bc9@linux.dev>
On Wed, Jun 10, 2026 at 03:44:32PM +0100, Usama Arif wrote:
>
>
>On 10/06/2026 14:48, David Hildenbrand (Arm) wrote:
>> On 6/10/26 15:01, Lance Yang wrote:
>>>
>>>
>>> On 2026/6/10 20:24, David Hildenbrand (Arm) wrote:
>>>> On 6/9/26 16:29, Usama Arif wrote:
>>>>>
>>>>>
>>>>>
>>>>> Hello!
>>>>>
>>>>> Just following up if there were any reviews/comments on this series!
>>>>>
>>>>> I know its a large series but was just checking if there was any
>>>>> feedback?
>>>>
>>>> It shall be reviewed. We just finished the mTHP khugepaged review to get it into
>>>> 7.2, so we've all been rather busy.
>>>
>>> Right, mTHP khugepaged was a rough one. Glad we got it over the line,
>>> but yeah, there's just been a lot of THP work lately. pretty nonstop ...
>>>
>
>Yeah its definitely a lot. I have set a target of leaving review comments on
>atleast 2 patches from mm per day myself, but even that can sometimes be
>difficult! I will try and help out more in reviews.
Awesome!
>>>> (I mean, just take a look at the THP-related flood of patches we are fighting
>>>> with on a daily basis, it's not funny anymore)
>>>>
>>>> This is clearly going to be 7.3 material, so there is plenty of time given that
>>>> the merge window is about to open soon.
>>>
>>> Usama, I'll try to make this one a priority too. Looks interesting :P
>
>Thanks Lance!
>
>>
>> I have two other bigger series to review, but I should soon get to this as well.
>>
>
>No worries at all! Thanks for the reviews! and yeah definitely 7.3.
>
>I will send this out again when 7.3-rc1 opens (rebased), so that the reviews wont be on
>outdated code which could cause some confusion.
After skimming through the whole series, probably PMD swap entries need
one bigger rethink ...
Emm ... same tricky bit keeps showing up ...
One PMD swap entry is easy to handle while the swapcache still has one
PMD-sized folio behind it. Once taht folio got split and reclaimed, the
512 swap slots need per-page handling :)
Maybe worth first pinning down the rule here.
Is a PMD swap entry supposed to mean "there is, or soon will be, one PMD-
sized folio behnid it", or is just a compact page-table encoding for
512 swap slot?
Without that rule being very clear, every caller has to guess how much
it can assume, and it is easy to miss one ...
So I stopped staring at the details for now, because the same issue keeps
popping up wearing a slightly different hat :)
Anyway, no clever answer from me here, not a swap expect :( Just pointing
out the pattern I keep runing into.
Thanks, Lance
prev parent reply other threads:[~2026-06-13 4:23 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-02 14:24 [v2 00/16] mm: PMD-level swap entries for anonymous THPs Usama Arif
2026-06-02 14:24 ` [v2 01/16] mm: add softleaf_to_pmd() and convert existing callers Usama Arif
2026-06-02 14:24 ` [v2 02/16] mm: extract mm_prepare_for_swap_entries() helper Usama Arif
2026-06-02 14:24 ` [v2 03/16] fs/proc: use softleaf_has_pfn() in pagemap PMD walker Usama Arif
2026-06-02 14:24 ` [v2 04/16] mm/huge_memory: move softleaf_to_folio() inside migration branch Usama Arif
2026-06-02 14:24 ` [v2 05/16] mm/migrate_device: move softleaf_to_folio() inside device-private branch Usama Arif
2026-06-02 14:24 ` [v2 06/16] mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_SUPPORTS_PMD_SOFTLEAF Usama Arif
2026-06-02 14:24 ` [v2 07/16] mm: add PMD swap entry detection support Usama Arif
2026-06-02 14:24 ` [v2 08/16] mm: add PMD swap entry splitting support Usama Arif
2026-06-02 14:24 ` [v2 09/16] mm: handle PMD swap entries in fork path Usama Arif
2026-06-02 14:24 ` [v2 10/16] mm: swap in PMD swap entries as whole THPs during swapoff Usama Arif
2026-06-02 14:24 ` [v2 11/16] mm: handle PMD swap entries in non-present PMD walkers Usama Arif
2026-06-12 6:45 ` Lance Yang
2026-06-12 15:05 ` Usama Arif
2026-06-12 15:21 ` Lance Yang
2026-06-02 14:24 ` [v2 12/16] mm: handle PMD swap entries in MADV_WILLNEED Usama Arif
2026-06-02 14:24 ` [v2 13/16] mm: handle PMD swap entries in UFFDIO_MOVE Usama Arif
2026-06-12 8:50 ` Lance Yang
2026-06-02 14:24 ` [v2 14/16] mm: handle PMD swap entry faults on swap-in Usama Arif
2026-06-02 14:24 ` [v2 15/16] mm: install PMD swap entries on swap-out Usama Arif
2026-06-12 14:21 ` Lance Yang
2026-06-02 14:24 ` [v2 16/16] selftests/mm: add PMD swap entry tests Usama Arif
2026-06-09 14:29 ` [v2 00/16] mm: PMD-level swap entries for anonymous THPs Usama Arif
2026-06-10 12:24 ` David Hildenbrand (Arm)
2026-06-10 13:01 ` Lance Yang
2026-06-10 13:48 ` David Hildenbrand (Arm)
2026-06-10 14:44 ` Usama Arif
2026-06-13 4:22 ` Lance Yang [this message]
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=20260613042232.93691-1-lance.yang@linux.dev \
--to=lance.yang@linux.dev \
--cc=akpm@linux-foundation.org \
--cc=alex@ghiti.fr \
--cc=baohua@kernel.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=baoquan.he@linux.dev \
--cc=chrisl@kernel.org \
--cc=david@kernel.org \
--cc=dev.jain@arm.com \
--cc=hannes@cmpxchg.org \
--cc=kas@kernel.org \
--cc=kasong@tencent.com \
--cc=kernel-team@meta.com \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ljs@kernel.org \
--cc=npache@redhat.com \
--cc=nphamcs@gmail.com \
--cc=riel@surriel.com \
--cc=ryan.roberts@arm.com \
--cc=shakeel.butt@linux.dev \
--cc=shikemeng@huaweicloud.com \
--cc=usama.arif@linux.dev \
--cc=vbabka@kernel.org \
--cc=willy@infradead.org \
--cc=ying.huang@linux.alibaba.com \
--cc=youngjun.park@lge.com \
--cc=ziy@nvidia.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.