From: Jann Horn <jannh@google.com>
To: Kairui Song <kasong@tencent.com>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
Pedro Falcato <pfalcato@suse.de>,
Matthew Wilcox <willy@infradead.org>,
Hugh Dickins <hughd@google.com>,
David Hildenbrand <david@redhat.com>,
Chris Li <chrisl@kernel.org>, Barry Song <baohua@kernel.org>,
Baoquan He <bhe@redhat.com>, Nhat Pham <nphamcs@gmail.com>,
Kemeng Shi <shikemeng@huaweicloud.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 3/3] mm/mincore: avoid touching the PTL
Date: Thu, 7 Aug 2025 18:02:17 +0200 [thread overview]
Message-ID: <CAG48ez114_bmuca2UL-g0ZY76-VqhL-4rQtJM_k0N2NJXE4vdg@mail.gmail.com> (raw)
In-Reply-To: <20250807152720.62032-4-ryncsn@gmail.com>
On Thu, Aug 7, 2025 at 5:27 PM Kairui Song <ryncsn@gmail.com> wrote:
> mincore only interested in the existence of a page, which is a
> changing state by nature, locking and making it stable is not needed.
> And now neither mincore_page or mincore_swap requires PTL, this PTL
> locking can be dropped.
This means you can race such that you end up looking at an unrelated
page of another process, right? And your patch intentionally allows
that to happen in order to make mincore() faster?
next prev parent reply other threads:[~2025-08-07 16:03 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-07 15:27 [RFC PATCH 0/3] mm/mincore: clean up swap cache helper and PTL Kairui Song
2025-08-07 15:27 ` [RFC PATCH 1/3] mm/mincore, swap: consolidate swap cache checking for mincore Kairui Song
2025-08-07 18:06 ` Nhat Pham
2025-08-07 18:23 ` Kairui Song
2025-08-07 15:27 ` [RFC PATCH 2/3] mm/mincore: use a helper for checking the swap cache Kairui Song
2025-08-07 15:27 ` [RFC PATCH 3/3] mm/mincore: avoid touching the PTL Kairui Song
2025-08-07 16:02 ` Jann Horn [this message]
2025-08-07 17:27 ` Kairui Song
2025-08-07 17:45 ` Jann Horn
2025-08-07 18:09 ` Kairui Song
2025-08-11 8:41 ` David Hildenbrand
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