From: "Lorenzo Stoakes (ARM)" <ljs@kernel.org>
To: 天狼 <rockeet@gmail.com>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
"Liam R. Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Jann Horn <jannh@google.com>,
Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>
Subject: Re: [RFC] madvise: best-effort deferred writeback for shared file mappings
Date: Wed, 30 Sep 2026 16:43:13 +0100 [thread overview]
Message-ID: <ar0r3QnZWzHdJt6Q@gremlin> (raw)
In-Reply-To: <CAAE3jtdHi7aSsJ62TpEjkxvwA-3TBLvr5i1ohCNg2aupND+_XQ@mail.gmail.com>
On Wed, Sep 30, 2026 at 11:29:09PM +0800, 天狼 wrote:
> Hi David, Lorenzo,
...
> Per-file deferred writeback would require minimal kernel changes and pose
> a very low risk, while offering enormous benefits.
I'm afraid the opposite is true.
The proposed expiry hint does nothing as soon as you hit the dirty background
threshold and in any case violates kernel writeback as explained.
And nothing you've proposed here is upstreamable.
A locked down simple process handing out memfds (as explained in detail in
other mail) or a named tmpfs file survives process crash perfectly fine and is
the correct shape of the solution.
This is what you should pursue.
--
Cheers, Lorenzo
next prev parent reply other threads:[~2026-09-30 15:43 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-28 7:07 [RFC] madvise: best-effort deferred writeback for shared file mappings 天狼
2026-09-28 11:29 ` David Hildenbrand (Arm)
2026-09-28 13:09 ` 天狼
2026-09-28 19:12 ` David Hildenbrand (Arm)
2026-09-29 4:06 ` 天狼
2026-09-29 6:59 ` David Hildenbrand (Arm)
2026-09-29 8:59 ` Lorenzo Stoakes (ARM)
2026-09-30 10:27 ` 天狼
2026-09-30 11:38 ` David Hildenbrand (Arm)
2026-09-30 12:08 ` Lorenzo Stoakes (ARM)
2026-09-30 12:11 ` Lorenzo Stoakes (ARM)
2026-09-30 14:14 ` 天狼
2026-09-30 14:24 ` Lorenzo Stoakes (ARM)
2026-09-30 15:33 ` Lorenzo Stoakes (ARM)
2026-09-30 15:29 ` 天狼
2026-09-30 15:43 ` Lorenzo Stoakes (ARM) [this message]
2026-09-30 16:38 ` Jan Kara
2026-10-01 4:28 ` 天狼
2026-10-01 8:35 ` Lorenzo Stoakes (ARM)
2026-10-01 13:21 ` 天狼
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