From: David Hildenbrand <david@redhat.com>
To: Mike Rapoport <rppt@kernel.org>, Matthew Wilcox <willy@infradead.org>
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: Freeing page flags
Date: Fri, 10 Jun 2022 19:39:32 +0200 [thread overview]
Message-ID: <688dccfb-ec4e-7522-b5ef-18a46337df91@redhat.com> (raw)
In-Reply-To: <Yosr35sTk3l9nBy1@kernel.org>
On 23.05.22 08:38, Mike Rapoport wrote:
> On Thu, May 12, 2022 at 09:54:59PM +0100, Matthew Wilcox wrote:
>> The LWN writeup [1] on merging the MGLRU reminded me that I need to send
>> out a plan for removing page flags that we can do without.
>>
>> 4. I think I can also consolidate PG_slab and PG_reserved into a "single
>> bit" (not really, but change the encoding so that effectively they only
>> take a single bit).
>
> PG_reserved could be a PageType, AFAIR no reserved pages are ever mapped to
> userspace
include/linux/page-flags.h documents for PG_reserved:
"Pages part of the kernel image (including vDSO)"
Further, vm_normal_page() contains a comment
"NOTE! We still have PageReserved() pages in the page tables. eg. VDSO
mappings can cause them to exist."
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2022-06-10 17:39 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-12 20:54 Freeing page flags Matthew Wilcox
2022-05-13 2:41 ` Josef Bacik
2022-05-13 3:39 ` Matthew Wilcox
2022-05-13 9:40 ` Luís Henriques
2022-05-13 12:53 ` Matthew Wilcox
2022-05-13 13:18 ` Luís Henriques
2022-05-13 13:21 ` Jeff Layton
2022-05-13 13:38 ` Matthew Wilcox
2022-05-13 13:57 ` Jeff Layton
2022-05-17 0:34 ` Xiubo Li
2022-05-13 13:17 ` Josef Bacik
2022-05-13 3:46 ` Yu Zhao
2022-05-14 6:10 ` Eric Biggers
2022-05-23 6:38 ` Mike Rapoport
2022-06-10 17:39 ` David Hildenbrand [this message]
2022-05-30 16:54 ` David Hildenbrand
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