From: Kiryl Shutsemau <kas@kernel.org>
To: Pedro Falcato <pfalcato@suse.de>
Cc: David Hildenbrand <david@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Nico Pache <npache@redhat.com>,
linux-mm@kvack.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
ziy@nvidia.com, baolin.wang@linux.alibaba.com,
lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com,
ryan.roberts@arm.com, dev.jain@arm.com, corbet@lwn.net,
rostedt@goodmis.org, mhiramat@kernel.org,
mathieu.desnoyers@efficios.com, akpm@linux-foundation.org,
baohua@kernel.org, willy@infradead.org, peterx@redhat.com,
wangkefeng.wang@huawei.com, usamaarif642@gmail.com,
sunnanyong@huawei.com, vishal.moola@gmail.com,
thomas.hellstrom@linux.intel.com, yang@os.amperecomputing.com,
aarcange@redhat.com, raquini@redhat.com,
anshuman.khandual@arm.com, catalin.marinas@arm.com,
tiwai@suse.de, will@kernel.org, dave.hansen@linux.intel.com,
jack@suse.cz, cl@gentwo.org, jglisse@google.com,
surenb@google.com, zokeefe@google.com, rientjes@google.com,
mhocko@suse.com, rdunlap@infradead.org, hughd@google.com,
richard.weiyang@gmail.com, lance.yang@linux.dev, vbabka@suse.cz,
rppt@kernel.org, jannh@google.com
Subject: Re: [PATCH v11 00/15] khugepaged: mTHP support
Date: Fri, 12 Sep 2025 16:44:17 +0100 [thread overview]
Message-ID: <y6ljs2byyzxkxqqxaf37kx5lqpshv47ndejksen2ihrvhcwksc@4r6f4sdtjd3g> (raw)
In-Reply-To: <k54teuep6r63gbgivpka32tk47zvzmy5thik2mekl5xpycvead@fth2lv4kuicg>
On Fri, Sep 12, 2025 at 04:39:02PM +0100, Kiryl Shutsemau wrote:
> > Shower thought: it might be in these cases especially where the FreeBSD
> > reservation system comes in handy - best effort allocating a THP, but not
> > actually mapping it as such until you really _know_ it is hot - and until
> > then, memory reclaim can just break your THP down if it really needs to.
>
> This is just silly. All downsides without benefit until maybe later. And
> for short-lived processes the "later" never comes.
The right way out is to get better info on access pattern from hardware.
For instance, if we move access bit out of page table entry and make it
independent of the actually mapping size that would give us much better
view on what actually is going on.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2025-09-12 15:44 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-12 3:27 Nico Pache
2025-09-12 3:27 ` [PATCH v11 01/15] khugepaged: rename hpage_collapse_* to collapse_* Nico Pache
2025-09-12 3:27 ` [PATCH v11 02/15] introduce collapse_single_pmd to unify khugepaged and madvise_collapse Nico Pache
2025-09-12 3:27 ` [PATCH v11 03/15] khugepaged: generalize hugepage_vma_revalidate for mTHP support Nico Pache
2025-09-12 3:27 ` [PATCH v11 04/15] khugepaged: generalize alloc_charge_folio() Nico Pache
2025-09-12 3:28 ` [PATCH v11 05/15] khugepaged: generalize __collapse_huge_page_* for mTHP support Nico Pache
2025-09-12 3:28 ` [PATCH v11 06/15] khugepaged: introduce collapse_max_ptes_none helper function Nico Pache
2025-09-12 13:35 ` Lorenzo Stoakes
2025-09-12 23:26 ` Nico Pache
2025-09-15 10:30 ` Lorenzo Stoakes
2025-09-12 3:28 ` [PATCH v11 07/15] khugepaged: generalize collapse_huge_page for mTHP collapse Nico Pache
2025-09-12 3:28 ` [PATCH v11 08/15] khugepaged: skip collapsing mTHP to smaller orders Nico Pache
2025-09-12 3:28 ` [PATCH v11 09/15] khugepaged: add per-order mTHP collapse failure statistics Nico Pache
2025-09-12 9:35 ` Baolin Wang
2025-09-12 3:28 ` [PATCH v11 10/15] khugepaged: improve tracepoints for mTHP orders Nico Pache
2025-09-12 3:28 ` [PATCH v11 11/15] khugepaged: introduce collapse_allowable_orders helper function Nico Pache
2025-09-12 9:24 ` Baolin Wang
2025-09-12 3:28 ` [PATCH v11 12/15] khugepaged: Introduce mTHP collapse support Nico Pache
2025-09-12 3:28 ` [PATCH v11 13/15] khugepaged: avoid unnecessary mTHP collapse attempts Nico Pache
2025-09-12 3:28 ` [PATCH v11 14/15] khugepaged: run khugepaged for all orders Nico Pache
2025-09-12 3:28 ` [PATCH v11 15/15] Documentation: mm: update the admin guide for mTHP collapse Nico Pache
2025-09-12 8:43 ` [PATCH v11 00/15] khugepaged: mTHP support Lorenzo Stoakes
2025-09-12 12:19 ` Kiryl Shutsemau
2025-09-12 12:25 ` David Hildenbrand
2025-09-12 13:37 ` Johannes Weiner
2025-09-12 13:46 ` David Hildenbrand
2025-09-12 14:01 ` Lorenzo Stoakes
2025-09-12 15:35 ` Pedro Falcato
2025-09-12 15:45 ` Lorenzo Stoakes
2025-09-12 15:15 ` Pedro Falcato
2025-09-12 15:38 ` Kiryl Shutsemau
2025-09-12 15:43 ` David Hildenbrand
2025-09-12 15:44 ` Kiryl Shutsemau [this message]
2025-09-12 15:51 ` David Hildenbrand
2025-09-15 13:43 ` Johannes Weiner
2025-09-15 14:45 ` David Hildenbrand
2025-09-12 23:31 ` Nico Pache
2025-09-15 9:22 ` Kiryl Shutsemau
2025-09-15 10:22 ` David Hildenbrand
2025-09-15 10:35 ` Lorenzo Stoakes
2025-09-15 10:39 ` David Hildenbrand
2025-09-15 10:40 ` Lorenzo Stoakes
2025-09-15 10:44 ` David Hildenbrand
2025-09-15 10:48 ` Lorenzo Stoakes
2025-09-15 10:52 ` David Hildenbrand
2025-09-15 10:59 ` Lorenzo Stoakes
2025-09-15 11:10 ` David Hildenbrand
2025-09-15 11:13 ` Lorenzo Stoakes
2025-09-15 11:16 ` David Hildenbrand
2025-09-15 12:16 ` Usama Arif
2025-09-15 10:43 ` Lorenzo Stoakes
2025-09-15 10:52 ` David Hildenbrand
2025-09-15 11:02 ` Lorenzo Stoakes
2025-09-15 11:14 ` David Hildenbrand
2025-09-15 11:23 ` Lorenzo Stoakes
2025-09-15 11:29 ` David Hildenbrand
2025-09-15 11:35 ` Lorenzo Stoakes
2025-09-15 11:45 ` David Hildenbrand
2025-09-15 12:01 ` Kiryl Shutsemau
2025-09-15 12:09 ` Lorenzo Stoakes
2025-09-15 11:41 ` Nico Pache
2025-09-15 12:59 ` David Hildenbrand
2025-09-12 13:47 ` David Hildenbrand
2025-09-12 14:28 ` David Hildenbrand
2025-09-12 14:35 ` Kiryl Shutsemau
2025-09-12 14:56 ` David Hildenbrand
2025-09-12 15:41 ` Kiryl Shutsemau
2025-09-12 15:45 ` David Hildenbrand
2025-09-12 15:51 ` Lorenzo Stoakes
2025-09-12 17:53 ` David Hildenbrand
2025-09-12 18:21 ` Lorenzo Stoakes
2025-09-13 0:28 ` Nico Pache
2025-09-15 10:44 ` Lorenzo Stoakes
2025-09-15 10:25 ` David Hildenbrand
2025-09-15 10:32 ` Lorenzo Stoakes
2025-09-15 10:37 ` David Hildenbrand
2025-09-15 10:46 ` Lorenzo Stoakes
2025-09-13 0:18 ` Nico Pache
2025-09-12 23:35 ` Nico Pache
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=y6ljs2byyzxkxqqxaf37kx5lqpshv47ndejksen2ihrvhcwksc@4r6f4sdtjd3g \
--to=kas@kernel.org \
--cc=Liam.Howlett@oracle.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=anshuman.khandual@arm.com \
--cc=baohua@kernel.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=catalin.marinas@arm.com \
--cc=cl@gentwo.org \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=dev.jain@arm.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=jack@suse.cz \
--cc=jannh@google.com \
--cc=jglisse@google.com \
--cc=lance.yang@linux.dev \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=lorenzo.stoakes@oracle.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mhocko@suse.com \
--cc=npache@redhat.com \
--cc=peterx@redhat.com \
--cc=pfalcato@suse.de \
--cc=raquini@redhat.com \
--cc=rdunlap@infradead.org \
--cc=richard.weiyang@gmail.com \
--cc=rientjes@google.com \
--cc=rostedt@goodmis.org \
--cc=rppt@kernel.org \
--cc=ryan.roberts@arm.com \
--cc=sunnanyong@huawei.com \
--cc=surenb@google.com \
--cc=thomas.hellstrom@linux.intel.com \
--cc=tiwai@suse.de \
--cc=usamaarif642@gmail.com \
--cc=vbabka@suse.cz \
--cc=vishal.moola@gmail.com \
--cc=wangkefeng.wang@huawei.com \
--cc=will@kernel.org \
--cc=willy@infradead.org \
--cc=yang@os.amperecomputing.com \
--cc=ziy@nvidia.com \
--cc=zokeefe@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