From: Byungchul Park <byungchul@sk.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
kernel_team@skhynix.com, akpm@linux-foundation.org,
ying.huang@intel.com, vernhao@tencent.com,
mgorman@techsingularity.net, hughd@google.com,
willy@infradead.org, david@redhat.com, peterz@infradead.org,
luto@kernel.org, tglx@linutronix.de, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, rjgolo@gmail.com
Subject: Re: [RFC PATCH v12 00/26] LUF(Lazy Unmap Flush) reducing tlb numbers over 90%
Date: Fri, 21 Feb 2025 08:23:29 +0900 [thread overview]
Message-ID: <20250220232329.GA39373@system.software.com> (raw)
In-Reply-To: <8accbd91-ca59-43f8-b190-7e1ac3df5e11@intel.com>
On Thu, Feb 20, 2025 at 07:15:44AM -0800, Dave Hansen wrote:
> On 2/19/25 21:20, Byungchul Park wrote:
> > I'm posting the latest version so that anyone can try luf mechanism if
> > wanted by any chance. However, I tagged RFC again because there are
> > still issues that should be resolved to merge to mainline:
>
> I don't see anything fundamentally different here from the last 11
> versions. I think the entire approach is dangerous and basically makes
> things impossible to debug. It's not clear that some of the failure
> scenarios that I've brought up in the past have actually been fixed.
Respect your opinion.
> What I've said here still stands:
>
> > https://lore.kernel.org/all/fab1dd64-c652-4160-93b4-7b483a8874da@intel.com/
>
> > I think tglx would call all of this "tinkering". The approach to this
> > series is to "fix" narrow, specific cases that reviewers point out, make
> > it compile, then send it out again, hoping someone will apply it.
> >
> > So, for me, until the approach to this series changes: NAK, for x86.
> > Andrew, please don't take this series. Or, if you do, please drop the
> > patch enabling it on x86.
>
> I think I'd also like to stop being cc'd on this. If LUF is merged into
I will un-cc you from the next spin.
Byungchul
> mainline and proven to work on arm64 or riscv for a year, I'd be happy
> to take another look at enabling it on x86. I think that's just about
> the only thing that would make me reconsider.
prev parent reply other threads:[~2025-02-20 23:23 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-20 5:20 Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 01/26] x86/tlb: add APIs manipulating tlb batch's arch data Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 02/26] arm64/tlbflush: " Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 03/26] riscv/tlb: " Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 04/26] x86/tlb, riscv/tlb, mm/rmap: separate arch_tlbbatch_clear() out of arch_tlbbatch_flush() Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 05/26] mm/buddy: make room for a new variable, luf_key, in struct page Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 06/26] mm: move should_skip_kasan_poison() to mm/internal.h Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 07/26] mm: introduce luf_ugen to be used as a global timestamp Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 08/26] mm: introduce luf_batch to be used as hash table to store luf meta data Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 09/26] mm: introduce API to perform tlb shootdown on exit from page allocator Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 10/26] mm: introduce APIs to check if the page allocation is tlb shootdownable Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 11/26] mm: deliver luf_key to pcp or buddy on free after unmapping Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 12/26] mm: delimit critical sections to take off pages from pcp or buddy alloctor Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 13/26] mm: introduce pend_list in struct free_area to track luf'd pages Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 14/26] mm/rmap: recognize read-only tlb entries during batched tlb flush Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 15/26] fs, filemap: refactor to gather the scattered ->write_{begin,end}() calls Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 16/26] mm: implement LUF(Lazy Unmap Flush) defering tlb flush when folios get unmapped Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 17/26] x86/tlb, riscv/tlb, arm64/tlbflush, mm: remove cpus from tlb shootdown that already have been done Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 18/26] mm/page_alloc: retry 3 times to take pcp pages on luf check failure Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 19/26] mm: skip luf tlb flush for luf'd mm that already has been done Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 20/26] mm, fs: skip tlb flushes for luf'd filemap " Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 21/26] mm: perform luf tlb shootdown per zone in batched manner Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 22/26] mm/page_alloc: not allow to tlb shootdown if !preemptable() && non_luf_pages_ok() Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 23/26] mm: separate move/undo parts from migrate_pages_batch() Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 24/26] mm/migrate: apply luf mechanism to unmapping during migration Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 25/26] mm/vmscan: apply luf mechanism to unmapping during folio reclaim Byungchul Park
2025-02-20 5:20 ` [RFC PATCH v12 26/26] mm/luf: implement luf debug feature Byungchul Park
2025-02-20 10:32 ` [RFC PATCH v12 00/26] LUF(Lazy Unmap Flush) reducing tlb numbers over 90% Hillf Danton
2025-02-20 10:51 ` Byungchul Park
2025-02-20 11:09 ` Byungchul Park
2025-02-20 11:49 ` Hillf Danton
2025-02-20 12:20 ` Byungchul Park
2025-02-20 12:40 ` Byungchul Park
2025-02-20 13:54 ` Matthew Wilcox
2025-02-20 15:09 ` Steven Rostedt
2025-02-20 22:53 ` Kent Overstreet
2025-02-20 23:05 ` Steven Rostedt
2025-02-20 23:21 ` Kent Overstreet
2025-02-20 23:25 ` Hillf Danton
2025-02-20 23:44 ` Steven Rostedt
[not found] ` <20250221230556.2479-1-hdanton@sina.com>
2025-02-22 7:16 ` Greg KH
[not found] ` <20250222101100.2531-1-hdanton@sina.com>
2025-02-22 13:57 ` Greg KH
2025-03-10 23:24 ` Dan Williams
2025-03-10 23:53 ` Barry Song
[not found] ` <20250619134922.1219-1-hdanton@sina.com>
2025-06-20 17:00 ` Dan Williams
2025-02-20 15:15 ` Dave Hansen
2025-02-20 15:29 ` Vlastimil Babka
2025-02-20 23:37 ` Byungchul Park
2025-02-26 11:30 ` RFC v12 rebased on v6.14-rc4 Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 01/25] x86/tlb: add APIs manipulating tlb batch's arch data Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 02/25] arm64/tlbflush: " Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 03/25] riscv/tlb: " Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 04/25] x86/tlb, riscv/tlb, mm/rmap: separate arch_tlbbatch_clear() out of arch_tlbbatch_flush() Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 05/25] mm/buddy: make room for a new variable, luf_key, in struct page Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 06/25] mm: move should_skip_kasan_poison() to mm/internal.h Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 07/25] mm: introduce luf_ugen to be used as a global timestamp Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 08/25] mm: introduce luf_batch to be used as hash table to store luf meta data Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 09/25] mm: introduce API to perform tlb shootdown on exit from page allocator Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 10/25] mm: introduce APIs to check if the page allocation is tlb shootdownable Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 11/25] mm: deliver luf_key to pcp or buddy on free after unmapping Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 12/25] mm: delimit critical sections to take off pages from pcp or buddy alloctor Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 13/25] mm: introduce pend_list in struct free_area to track luf'd pages Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 14/25] mm/rmap: recognize read-only tlb entries during batched tlb flush Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 15/25] fs, filemap: refactor to gather the scattered ->write_{begin,end}() calls Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 16/25] mm: implement LUF(Lazy Unmap Flush) defering tlb flush when folios get unmapped Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 17/25] x86/tlb, riscv/tlb, arm64/tlbflush, mm: remove cpus from tlb shootdown that already have been done Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 18/25] mm/page_alloc: retry 3 times to take pcp pages on luf check failure Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 19/25] mm: skip luf tlb flush for luf'd mm that already has been done Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 20/25] mm, fs: skip tlb flushes for luf'd filemap " Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 21/25] mm: perform luf tlb shootdown per zone in batched manner Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 22/25] mm/page_alloc: not allow to tlb shootdown if !preemptable() && non_luf_pages_ok() Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 23/25] mm/migrate: apply luf mechanism to unmapping during migration Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 24/25] mm/vmscan: apply luf mechanism to unmapping during folio reclaim Byungchul Park
2025-02-26 12:03 ` [RFC PATCH v12 based on v6.14-rc4 25/25] mm/luf: implement luf debug feature Byungchul Park
2025-02-26 11:33 ` RFC v12 rebased on mm-unstable as of Feb 21, 2025 Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 01/25] x86/tlb: add APIs manipulating tlb batch's arch data Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 02/25] arm64/tlbflush: " Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 03/25] riscv/tlb: " Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 04/25] x86/tlb, riscv/tlb, mm/rmap: separate arch_tlbbatch_clear() out of arch_tlbbatch_flush() Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 05/25] mm/buddy: make room for a new variable, luf_key, in struct page Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 06/25] mm: move should_skip_kasan_poison() to mm/internal.h Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 07/25] mm: introduce luf_ugen to be used as a global timestamp Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 08/25] mm: introduce luf_batch to be used as hash table to store luf meta data Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 09/25] mm: introduce API to perform tlb shootdown on exit from page allocator Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 10/25] mm: introduce APIs to check if the page allocation is tlb shootdownable Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 11/25] mm: deliver luf_key to pcp or buddy on free after unmapping Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 12/25] mm: delimit critical sections to take off pages from pcp or buddy alloctor Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 13/25] mm: introduce pend_list in struct free_area to track luf'd pages Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 14/25] mm/rmap: recognize read-only tlb entries during batched tlb flush Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 15/25] fs, filemap: refactor to gather the scattered ->write_{begin,end}() calls Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 16/25] mm: implement LUF(Lazy Unmap Flush) defering tlb flush when folios get unmapped Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 17/25] x86/tlb, riscv/tlb, arm64/tlbflush, mm: remove cpus from tlb shootdown that already have been done Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 18/25] mm/page_alloc: retry 3 times to take pcp pages on luf check failure Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 19/25] mm: skip luf tlb flush for luf'd mm that already has been done Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 20/25] mm, fs: skip tlb flushes for luf'd filemap " Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 21/25] mm: perform luf tlb shootdown per zone in batched manner Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 22/25] mm/page_alloc: not allow to tlb shootdown if !preemptable() && non_luf_pages_ok() Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 23/25] mm/migrate: apply luf mechanism to unmapping during migration Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 24/25] mm/vmscan: apply luf mechanism to unmapping during folio reclaim Byungchul Park
2025-02-26 12:01 ` [RFC PATCH v12 based on mm-unstable as of Feb 21, 2025 25/25] mm/luf: implement luf debug feature Byungchul Park
2025-02-22 1:14 ` [RFC PATCH v12 00/26] LUF(Lazy Unmap Flush) reducing tlb numbers over 90% Shakeel Butt
2025-02-20 23:23 ` Byungchul Park [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=20250220232329.GA39373@system.software.com \
--to=byungchul@sk.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=david@redhat.com \
--cc=hughd@google.com \
--cc=kernel_team@skhynix.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rjgolo@gmail.com \
--cc=tglx@linutronix.de \
--cc=vernhao@tencent.com \
--cc=willy@infradead.org \
--cc=ying.huang@intel.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