From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Josef Bacik <josef@toxicpanda.com>,
Andrew Morton <akpm@linux-foundation.org>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Michal Hocko <mhocko@suse.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
Jan Kara <jack@suse.cz>, Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Nico Pache <nico.pache@linux.dev>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Usama Arif <usama.arif@linux.dev>,
Kiryl Shutsemau <kas@kernel.org>,
Matthew Brost <matthew.brost@intel.com>,
Joshua Hahn <joshua.hahnjy@gmail.com>,
Byungchul Park <byungchul@sk.com>,
Gregory Price <gourry@gourry.net>,
Ying Huang <ying.huang@linux.alibaba.com>,
Alistair Popple <apopple@nvidia.com>,
Peter Xu <peterx@redhat.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Song Liu <songliubraving@fb.com>, Rik van Riel <riel@surriel.com>,
Hugh Dickins <hughd@google.com>, Will Deacon <will@kernel.org>,
"Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
Nick Piggin <npiggin@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Kevin Tian <kevin.tian@intel.com>,
"Joerg Roedel (AMD)" <joro@8bytes.org>,
Robin Murphy <robin.murphy@arm.com>,
Steve Sistare <steven.sistare@oracle.com>,
John Hubbard <jhubbard@nvidia.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org,
iommu@lists.linux.dev, stable@vger.kernel.org
Subject: Re: [PATCH 2/5] mm: limit pagecache folio refcount when splicing into pipes
Date: Fri, 6 Nov 2026 21:45:54 +0100 [thread overview]
Message-ID: <25e0354e-f6b4-4d42-b5ec-1656c9df8308@kernel.org> (raw)
In-Reply-To: <20261106204310.GK663069@ziepe.ca>
On 11/6/26 21:43, Jason Gunthorpe wrote:
> On Fri, Nov 06, 2026 at 09:09:10PM +0100, David Hildenbrand (Arm) wrote:
>> On 11/6/26 18:58, Josef Bacik wrote:
>>>
>>> Since you're here anyway can you change this to something other than
>>> WARN_ON_ONCE, since that results in an OOPS with panic_on_warn set?
>>> Thanks,
>>
>> If it actually turns negative (or 0) with out changes, we had an overflow and
>> for sure want to know about it :)
>
> Yeah, didn't you get Docs merged to clarify WARN_ON is fine if
> userspace can't trigger it?
Yes, I pointed Josef at it off-list.
--
Cheers,
David
next prev parent reply other threads:[~2026-11-06 20:46 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-05 13:10 [PATCH 0/5] mm: limit pagecache folio refcount David Hildenbrand (Arm)
2026-11-05 13:10 ` [PATCH 1/5] mm: limit pagecache folio refcount when mapping pages David Hildenbrand (Arm)
2026-11-06 9:11 ` Lance Yang
2026-11-06 9:42 ` Jose A. Perez de Azpillaga
2026-11-06 10:05 ` David Hildenbrand (Arm)
2026-11-06 10:06 ` Lance Yang
2026-11-06 21:23 ` David Hildenbrand (Arm)
2026-11-06 12:38 ` Kiryl Shutsemau
2026-11-06 20:54 ` David Hildenbrand (Arm)
2026-11-05 13:10 ` [PATCH 2/5] mm: limit pagecache folio refcount when splicing into pipes David Hildenbrand (Arm)
2026-11-06 9:50 ` Jose A. Perez de Azpillaga
2026-11-06 10:03 ` Lance Yang
2026-11-06 21:57 ` David Hildenbrand (Arm)
2026-11-06 17:58 ` Josef Bacik
2026-11-06 20:09 ` David Hildenbrand (Arm)
2026-11-06 20:43 ` Jason Gunthorpe
2026-11-06 20:45 ` David Hildenbrand (Arm) [this message]
2026-11-05 13:10 ` [PATCH 3/5] mm/mmu_gather: flush pending references early before the folio limit David Hildenbrand (Arm)
2026-11-06 9:56 ` Jose A. Perez de Azpillaga
2026-11-06 15:15 ` Lance Yang
2026-11-05 13:10 ` [PATCH 4/5] iommufd: fix cleanup when adding memfd folio pins fails David Hildenbrand (Arm)
2026-11-06 15:39 ` Lance Yang
2026-11-06 20:46 ` Jason Gunthorpe
2026-11-05 13:10 ` [PATCH 5/5] mm/gup: limit pagecache folio refcount when grabbing references David Hildenbrand (Arm)
2026-11-06 10:13 ` Jose A. Perez de Azpillaga
2026-11-06 22:42 ` David Hildenbrand (Arm)
2026-11-05 17:51 ` [PATCH 0/5] mm: limit pagecache folio refcount David Hildenbrand (Arm)
2026-11-06 19:49 ` Josef Bacik
2026-11-06 20:31 ` David Hildenbrand (Arm)
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