From: Peter Xu <peterx@redhat.com>
To: David Hildenbrand <david@redhat.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Muchun Song <songmuchun@bytedance.com>,
John Hubbard <jhubbard@nvidia.com>,
Andrea Arcangeli <aarcange@redhat.com>,
James Houghton <jthoughton@google.com>,
Jann Horn <jannh@google.com>, Rik van Riel <riel@surriel.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>
Subject: Re: [PATCH v2 08/10] mm/hugetlb: Make walk_hugetlb_range() safe to pmd unshare
Date: Fri, 9 Dec 2022 09:39:30 -0500 [thread overview]
Message-ID: <Y5NIoqXlAvrXkCOM@x1n> (raw)
In-Reply-To: <72a62bf5-7633-f35f-75fd-0222fd0ab49f@redhat.com>
On Fri, Dec 09, 2022 at 11:24:55AM +0100, David Hildenbrand wrote:
> For such cases, it would be good to have any evidence that it really helps.
I don't know much on the s390 path, but if a process has a large hugetlb
vma, even MADV_DONTNEED will be blocked for whatever long time if there's
another process or thread scanning pagemap for this vma.
Would this justify a bit?
It's just that the vma lock is taken write far more than mmap_lock taken
write I think, meanwhile what we need here is only release the lock and
retake, nothing else. It didn't make things over complicated, IMO.
No strong ipinion from my side, as I said to me it's really low hanging
fruit. If you still think that doesn't justify and if Mike doesn't have a
preference either I can just drop it for later.
--
Peter Xu
next prev parent reply other threads:[~2022-12-09 14:39 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-07 20:30 [PATCH v2 00/10] mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare Peter Xu
2022-12-07 20:30 ` [PATCH v2 01/10] mm/hugetlb: Let vma_offset_start() to return start Peter Xu
2022-12-07 21:21 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 02/10] mm/hugetlb: Don't wait for migration entry during follow page Peter Xu
2022-12-07 22:03 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 03/10] mm/hugetlb: Document huge_pte_offset usage Peter Xu
2022-12-07 20:49 ` John Hubbard
2022-12-08 13:05 ` David Hildenbrand
2022-12-07 20:30 ` [PATCH v2 04/10] mm/hugetlb: Move swap entry handling into vma lock when faulted Peter Xu
2022-12-07 22:36 ` John Hubbard
2022-12-07 22:43 ` Peter Xu
2022-12-07 23:05 ` John Hubbard
2022-12-08 20:28 ` Peter Xu
2022-12-08 20:31 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 05/10] mm/hugetlb: Make userfaultfd_huge_must_wait() safe to pmd unshare Peter Xu
2022-12-07 23:19 ` John Hubbard
2022-12-07 23:44 ` Peter Xu
2022-12-07 23:54 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 06/10] mm/hugetlb: Make hugetlb_follow_page_mask() " Peter Xu
2022-12-07 23:21 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 07/10] mm/hugetlb: Make follow_hugetlb_page() " Peter Xu
2022-12-07 23:25 ` John Hubbard
2022-12-07 20:30 ` [PATCH v2 08/10] mm/hugetlb: Make walk_hugetlb_range() " Peter Xu
2022-12-07 20:34 ` John Hubbard
2022-12-08 13:14 ` David Hildenbrand
2022-12-08 20:47 ` Peter Xu
2022-12-08 21:20 ` Peter Xu
2022-12-09 10:24 ` David Hildenbrand
2022-12-09 14:39 ` Peter Xu [this message]
2022-12-09 15:18 ` David Hildenbrand
2022-12-07 20:31 ` [PATCH v2 09/10] mm/hugetlb: Introduce hugetlb_walk() Peter Xu
2022-12-07 22:27 ` Mike Kravetz
2022-12-08 0:12 ` John Hubbard
2022-12-08 21:01 ` Peter Xu
2022-12-08 21:50 ` John Hubbard
2022-12-08 23:21 ` Peter Xu
2022-12-07 20:31 ` [PATCH v2 10/10] mm/hugetlb: Document why page_vma_mapped_walk() is safe to walk Peter Xu
2022-12-08 0:16 ` John Hubbard
2022-12-08 21:05 ` Peter Xu
2022-12-08 21:54 ` John Hubbard
2022-12-08 22:21 ` Peter Xu
2022-12-09 0:24 ` John Hubbard
2022-12-09 0:43 ` Peter Xu
2022-12-08 13:16 ` David Hildenbrand
2022-12-08 21:05 ` Peter Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y5NIoqXlAvrXkCOM@x1n \
--to=peterx@redhat.com \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=jannh@google.com \
--cc=jhubbard@nvidia.com \
--cc=jthoughton@google.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mike.kravetz@oracle.com \
--cc=nadav.amit@gmail.com \
--cc=riel@surriel.com \
--cc=songmuchun@bytedance.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).