From: Matthew Wilcox <willy@infradead.org>
To: "Barry Song (Xiaomi)" <baohua@kernel.org>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org, david@kernel.org,
ljs@kernel.org, liam@infradead.org, vbabka@kernel.org,
rppt@kernel.org, surenb@google.com, mhocko@suse.com,
jack@suse.cz, pfalcato@suse.de, wanglian@kylinos.cn,
chentao@kylinos.cn, lianux.mm@gmail.com, kunwu.chan@gmail.com,
liyangouwen1@oppo.com, chrisl@kernel.org, kasong@tencent.com,
shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com,
youngjun.park@lge.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, loongarch@lists.linux.dev,
linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
linux-s390@vger.kernel.org
Subject: Re: [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance
Date: Thu, 30 Apr 2026 13:37:14 +0100 [thread overview]
Message-ID: <afNM-gIqxpyJ6ro7@casper.infradead.org> (raw)
In-Reply-To: <20260430040427.4672-1-baohua@kernel.org>
On Thu, Apr 30, 2026 at 12:04:22PM +0800, Barry Song (Xiaomi) wrote:
> (1) If we need to wait for I/O completion, we still drop the per-VMA lock, as
> current page fault handling already does. Holding it for too long may introduce
> various priority inversion issues on mobile devices. After I/O completes, we
> retry the page fault with the per-VMA lock, rather than falling back to
> mmap_lock.
You're going to have to do better than that. You know I hate the
additional complexity you're adding. You need to explain why my idea of
ripping out all the complexity now that we have per-VMA locks doesn't
work.
next prev parent reply other threads:[~2026-04-30 12:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-30 4:04 [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Barry Song (Xiaomi)
2026-04-30 4:04 ` [PATCH v2 1/5] mm/filemap: Retry fault by VMA lock if the lock was released for I/O Barry Song (Xiaomi)
2026-04-30 4:04 ` [PATCH v2 2/5] mm/swapin: Retry swapin " Barry Song (Xiaomi)
2026-04-30 4:04 ` [PATCH v2 3/5] mm: Move folio_lock_or_retry() and drop __folio_lock_or_retry() Barry Song (Xiaomi)
2026-04-30 4:04 ` [PATCH v2 4/5] mm: Don't retry page fault if folio is uptodate during swap-in Barry Song (Xiaomi)
2026-04-30 12:35 ` Matthew Wilcox
2026-05-01 16:11 ` Matthew Wilcox
2026-04-30 4:04 ` [PATCH v2 5/5] mm/filemap: Avoid retrying page faults on uptodate folios in filemap faults Barry Song (Xiaomi)
2026-04-30 12:37 ` Matthew Wilcox [this message]
2026-04-30 22:49 ` [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Barry Song
2026-05-01 14:56 ` Matthew Wilcox
2026-05-01 17:44 ` Barry Song
2026-05-01 17:57 ` Matthew Wilcox
2026-05-01 18:25 ` Barry Song
2026-05-01 19:39 ` Matthew Wilcox
2026-05-03 20:39 ` Barry Song
2026-05-03 13:13 ` Jan Kara
2026-05-03 19:55 ` Barry Song
2026-05-04 13:03 ` Jan Kara
2026-05-01 15:52 ` Lorenzo Stoakes
2026-05-01 16:06 ` Matthew Wilcox
2026-05-01 17:09 ` Lorenzo Stoakes
2026-05-01 17:59 ` Barry Song
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