From: David Hildenbrand <david@redhat.com>
To: Nadav Amit <nadav.amit@gmail.com>
Cc: "zhangliang (AG)" <zhangliang5@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
wangzhigang17@huawei.com, Matthew Wilcox <willy@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] mm: reuse the unshared swapcache page in do_wp_page
Date: Thu, 20 Jan 2022 19:19:51 +0100 [thread overview]
Message-ID: <0b734af9-d2c3-acef-3804-3a87e1e61a59@redhat.com> (raw)
In-Reply-To: <6225EAFF-B323-4DC5-AC4C-885B29ED7261@gmail.com>
>> Sounds good? At least to me. If only swap/migration entries wouldn't be
>> harder to handle than I'd wish, that's why it's taking a little and will
>> take a little longer.
>
> Thanks for the quick response. I would have to see the logic to set/clear
> PageAnonExclusive to fully understand how things are handled.
>
I'll let you know as soon as I have something. I'll most probably share
a document explaining the design first.
> BTW, I just saw this patch form PeterZ [1] that seems to be related, as
> it deals with changing protection on pinned pages.
Unfortunately the use of page_maybe_dma_pinned() is racy, as we can race
with GUP fast. It's a problem for vmscan which currently relies on it
for correctness. For migration, it might be good enough as we should
fail later when trying to freeze the refcount.
>
>
> [1] https://lore.kernel.org/linux-mm/20220120160822.666778608@infradead.org/
>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2022-01-20 18:19 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 14:03 [PATCH] mm: reuse the unshared swapcache page in do_wp_page Liang Zhang
2022-01-13 14:39 ` Matthew Wilcox
2022-01-13 14:46 ` David Hildenbrand
2022-01-13 15:02 ` Matthew Wilcox
2022-01-13 15:04 ` David Hildenbrand
2022-01-13 16:37 ` Linus Torvalds
2022-01-13 16:48 ` David Hildenbrand
2022-01-13 17:14 ` Linus Torvalds
2022-01-13 17:25 ` David Hildenbrand
2022-01-13 17:44 ` Linus Torvalds
2022-01-13 17:55 ` David Hildenbrand
2022-01-13 18:55 ` Linus Torvalds
2022-01-13 21:07 ` Matthew Wilcox
2022-01-13 22:21 ` Linus Torvalds
2022-01-14 5:00 ` zhangliang (AG)
2022-01-14 11:23 ` David Hildenbrand
2022-01-17 2:11 ` zhangliang (AG)
2022-01-17 12:58 ` David Hildenbrand
2022-01-17 13:31 ` zhangliang (AG)
2022-01-20 14:15 ` David Hildenbrand
2022-01-20 14:39 ` Matthew Wilcox
2022-01-20 15:26 ` David Hildenbrand
2022-01-20 15:36 ` Matthew Wilcox
2022-01-20 15:39 ` David Hildenbrand
2022-01-20 15:45 ` Matthew Wilcox
2022-01-20 15:51 ` David Hildenbrand
2022-01-20 16:09 ` Matthew Wilcox
2022-01-20 16:35 ` David Hildenbrand
2022-01-20 15:37 ` Linus Torvalds
2022-01-20 15:46 ` David Hildenbrand
2022-01-20 17:22 ` Linus Torvalds
2022-01-20 17:49 ` David Hildenbrand
2022-01-20 17:48 ` Nadav Amit
2022-01-20 18:00 ` David Hildenbrand
2022-01-20 18:11 ` Nadav Amit
2022-01-20 18:19 ` David Hildenbrand [this message]
2022-01-20 19:55 ` David Hildenbrand
2022-01-20 20:07 ` Matthew Wilcox
2022-01-20 20:09 ` David Hildenbrand
2022-01-20 20:37 ` David Hildenbrand
2022-01-20 20:46 ` Nadav Amit
2022-01-20 20:49 ` David Hildenbrand
2022-01-21 9:01 ` David Hildenbrand
2022-01-21 17:43 ` Nadav Amit
2022-01-20 20:18 ` David Hildenbrand
2022-01-14 3:29 ` zhangliang (AG)
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