From: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
To: David Hildenbrand <david@redhat.com>
Cc: Barry Song <21cnbao@gmail.com>,
Nicolas Geoffray <ngeoffray@google.com>,
Lokesh Gidra <lokeshgidra@google.com>,
Harry Yoo <harry.yoo@oracle.com>,
Suren Baghdasaryan <surenb@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@surriel.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
Linux-MM <linux-mm@kvack.org>,
Kalesh Singh <kaleshsingh@google.com>,
SeongJae Park <sj@kernel.org>, Barry Song <v-songbaohua@oppo.com>,
Peter Xu <peterx@redhat.com>
Subject: Re: [DISCUSSION] anon_vma root lock contention and per anon_vma lock
Date: Thu, 11 Sep 2025 09:34:09 +0100 [thread overview]
Message-ID: <974c11ff-a4b6-4273-8ecc-da80b88d5847@lucifer.local> (raw)
In-Reply-To: <fc37efe2-53a2-483b-8c59-bccafae81d97@redhat.com>
On Thu, Sep 11, 2025 at 10:14:26AM +0200, David Hildenbrand wrote:
> To summarize, are you proposing a similar locking scheme like we have for mm
> vs. vma here for anon-vma root vs. anon-vma?
I don't think that can work, because when holding the write lock we will drop
interval edges, not sure how we can possibly have concurrent readers at this
point.
And for write you'd have to analagously hold the root anon_vma write lock so
that'd be no faster.
I think really this problem speaks to fundamental issues with how anon_vma's are
implemented (that being the case is why I have such an interest in attacking
this problem).
I can try implementing some ideas in relation to this, as I do hope that I can
find incremental ways of doing so... - Barry I guess it's fairly easy to repro
some of these contention issues to test ideas out?
Cheers, Lorenzo
next prev parent reply other threads:[~2025-09-11 8:34 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-11 7:17 Barry Song
2025-09-11 8:14 ` David Hildenbrand
2025-09-11 8:34 ` Lorenzo Stoakes [this message]
2025-09-11 9:18 ` Barry Song
2025-09-11 10:47 ` Lorenzo Stoakes
2025-09-11 8:28 ` Lorenzo Stoakes
2025-09-11 18:22 ` Jann Horn
2025-09-12 4:49 ` Lorenzo Stoakes
2025-09-12 11:37 ` Jann Horn
2025-09-12 11:56 ` Lorenzo Stoakes
2025-09-14 23:53 ` Matthew Wilcox
2025-09-15 0:23 ` Barry Song
2025-09-15 1:47 ` Suren Baghdasaryan
2025-09-15 8:41 ` Lorenzo Stoakes
2025-09-15 2:50 ` Matthew Wilcox
2025-09-15 5:17 ` David Hildenbrand
2025-09-15 9:42 ` Lorenzo Stoakes
2025-09-15 10:29 ` David Hildenbrand
2025-09-15 10:56 ` Lorenzo Stoakes
2025-09-15 9:22 ` Lorenzo Stoakes
2025-09-15 10:41 ` David Hildenbrand
2025-09-15 10:51 ` Lorenzo Stoakes
2025-09-15 8:57 ` Lorenzo Stoakes
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