From: Harry Yoo <harry@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>,
Kiryl Shutsemau <kirill@shutemov.name>,
Ilya Gladyshev <ilya.gladyshev@linux.dev>,
Matthew Wilcox <willy@infradead.org>,
Lorenzo Stoakes <ljs@kernel.org>,
Luis Chamberlain <mcgrof@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Pedro Falcato <pfalcato@suse.de>
Subject: Re: Improve page refcount scalability
Date: Wed, 14 Oct 2026 01:10:16 +0100 [thread overview]
Message-ID: <as690Xcu7FxIDYjf@thinkpad> (raw)
In-Reply-To: <CAHk-=wjLjgfwgSZ1RDk4YdNFcV0ntosMO5AmBoHD76Zb3HFY7Q@mail.gmail.com>
On Tue, Oct 13, 2026 at 11:43:14AM -0700, Linus Torvalds wrote:
> Comments?
There should be a limitation on how much memory can be submitted to RCU
by the page cache, otherwise will be a corner case where we have too
much unreclaimable memory waiting for the RCU subsystem to free them.
There's a similar feature, dirty throttling: when a process dirties
memory in page cache much faster than the storage can handle IO,
the kernel throttles it, otherwise it'll allow generating unbounded
amount of unreclaimable memory.
For the same reason, when a process tries to create RCU-delay-freed
pages much faster than RCU can free memory, the kernel needs to limit
that.
--
Cheers,e
Harry / Hyeonggon
next prev parent reply other threads:[~2026-10-14 0:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-13 18:43 Improve page refcount scalability Linus Torvalds
2026-10-13 21:03 ` Matthew Wilcox
2026-10-13 21:26 ` Linus Torvalds
2026-10-13 23:20 ` Paul E. McKenney
2026-10-13 22:43 ` Kiryl Shutsemau
2026-10-13 23:39 ` Linus Torvalds
2026-10-14 0:10 ` Harry Yoo [this message]
2026-10-14 1:01 ` Linus Torvalds
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