From: Kiryl Shutsemau <kas@kernel.org>
To: Dave Hansen <dave.hansen@intel.com>
Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org,
x86@kernel.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Mike Rapoport <rppt@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Usama Arif <usama.arif@linux.dev>
Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86
Date: Thu, 19 Feb 2026 22:05:37 +0000 [thread overview]
Message-ID: <aZeFeAP9Zh-9q7pH@thinkstation> (raw)
In-Reply-To: <46817fe5-7166-4734-bad3-3109cc7feb1e@intel.com>
On Thu, Feb 19, 2026 at 09:08:57AM -0800, Dave Hansen wrote:
> On 2/19/26 07:08, Kiryl Shutsemau wrote:
> > - The order-0 page size cuts struct page overhead by a factor of 16. From
> > ~1.6% of RAM to ~0.1%;
> ...
> But, it will mostly be getting better performance at the _cost_ of
> consuming more RAM, not saving RAM.
That's fair.
The problem with struct page memory consumption is that it is static and
cannot be reclaimed. You pay the struct page tax no matter what.
Page cache rounding overhead can be large, but a motivated userspace can
keep it under control by avoiding splitting a dataset into many small
files. And this memory is reclaimable.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2026-02-19 22:05 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-19 15:08 Kiryl Shutsemau
2026-02-19 15:17 ` Peter Zijlstra
2026-02-19 15:20 ` Peter Zijlstra
2026-02-19 15:27 ` Kiryl Shutsemau
2026-02-19 15:33 ` Pedro Falcato
2026-02-19 15:50 ` Kiryl Shutsemau
2026-02-19 15:53 ` David Hildenbrand (Arm)
2026-02-19 19:31 ` Pedro Falcato
2026-02-19 15:39 ` David Hildenbrand (Arm)
2026-02-19 15:54 ` Kiryl Shutsemau
2026-02-19 16:09 ` David Hildenbrand (Arm)
2026-02-20 2:55 ` Zi Yan
2026-02-19 17:09 ` Kiryl Shutsemau
2026-02-20 10:24 ` David Hildenbrand (Arm)
2026-02-20 12:07 ` Kiryl Shutsemau
2026-02-20 16:30 ` David Hildenbrand (Arm)
2026-02-20 19:33 ` Kalesh Singh
2026-02-19 23:24 ` Kalesh Singh
2026-02-20 12:10 ` Kiryl Shutsemau
2026-02-20 19:21 ` Kalesh Singh
2026-02-19 17:08 ` Dave Hansen
2026-02-19 22:05 ` Kiryl Shutsemau [this message]
2026-02-20 3:28 ` Liam R. Howlett
2026-02-20 12:33 ` Kiryl Shutsemau
2026-02-20 15:17 ` Liam R. Howlett
2026-02-20 15:50 ` Kiryl Shutsemau
2026-02-19 17:30 ` Dave Hansen
2026-02-19 22:14 ` Kiryl Shutsemau
2026-02-19 22:21 ` Dave Hansen
2026-02-19 17:47 ` Matthew Wilcox
2026-02-19 22:26 ` Kiryl Shutsemau
2026-02-20 9:04 ` David Laight
2026-02-20 12:12 ` Kiryl Shutsemau
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