From: "Garg, Shivank" <shivankg@amd.com>
To: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
Matthew Wilcox <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@redhat.com>, Zi Yan <ziy@nvidia.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Nico Pache <npache@redhat.com>,
Ryan Roberts <ryan.roberts@arm.com>, Dev Jain <dev.jain@arm.com>,
Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Zach O'Keefe <zokeefe@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org,
Branden Moore <Branden.Moore@amd.com>
Subject: Re: [PATCH 1/2] mm/khugepaged: do synchronous writeback for MADV_COLLAPSE
Date: Mon, 10 Nov 2025 19:50:17 +0530 [thread overview]
Message-ID: <39c8a4ed-53b5-48e3-baea-f67cc1e8be4f@amd.com> (raw)
In-Reply-To: <b7313a45-c36e-4390-a0b8-46f412474f86@lucifer.local>
On 11/10/2025 7:22 PM, Lorenzo Stoakes wrote:
> On Mon, Nov 10, 2025 at 01:47:10PM +0000, Matthew Wilcox wrote:
>> On Mon, Nov 10, 2025 at 11:32:53AM +0000, Shivank Garg wrote:
>>> When MADV_COLLAPSE is called on file-backed mappings (e.g., executable
>>> text sections), the pages may still be dirty from recent writes. The
>>
>> That explanation derails my brain entirely. Text isn't writable! How
>> can the pages be dirty and file-backed text?
>
> Because they just compiled it and it's not been written back to disk yet :)
Hi,
It's not about compilation. My binaries are already compiled.
The issue is copying those binary to a freshly mounted filesystem.
The page cache folios remain dirty until background writeback completes.
Reproduces 100% for me: fresh XFS/EXT4 mount -> copy binary -> execute -> MADV_COLLAPSE fails.
Detail logs: https://lore.kernel.org/all/0b84865c-5b23-4be6-9902-af9d5e63c182@amd.com
Thanks,
Shivank
next prev parent reply other threads:[~2025-11-10 14:20 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-10 11:32 [PATCH 1/2] mm/khugepaged: do synchronous writeback for MADV_COLLAPSE Shivank Garg
2025-11-10 11:32 ` [PATCH 2/2] mm/khugepaged: return EAGAIN for transient dirty pages in MADV_COLLAPSE Shivank Garg
2025-11-10 11:56 ` Lorenzo Stoakes
2025-11-19 10:25 ` Garg, Shivank
2025-11-19 18:16 ` Lorenzo Stoakes
2025-11-20 7:03 ` Garg, Shivank
2025-11-10 13:46 ` Dev Jain
2025-11-19 7:00 ` Garg, Shivank
2025-11-10 12:01 ` [PATCH 1/2] mm/khugepaged: do synchronous writeback for MADV_COLLAPSE Lorenzo Stoakes
2025-11-10 13:07 ` Garg, Shivank
2025-11-10 13:22 ` Lorenzo Stoakes
2025-11-10 16:06 ` Lorenzo Stoakes
2025-11-10 16:55 ` Zi Yan
2025-11-10 19:40 ` Garg, Shivank
2025-11-10 19:48 ` Lorenzo Stoakes
2025-11-10 19:53 ` Lorenzo Stoakes
2025-11-10 21:16 ` Lorenzo Stoakes
2025-11-10 21:56 ` Zi Yan
2025-11-10 22:03 ` Lorenzo Stoakes
2025-11-11 5:26 ` Garg, Shivank
2025-11-10 13:24 ` Dev Jain
2025-11-10 13:36 ` Lorenzo Stoakes
2025-11-11 3:41 ` Dev Jain
2025-11-10 13:47 ` Matthew Wilcox
2025-11-10 13:52 ` Lorenzo Stoakes
2025-11-10 14:17 ` Matthew Wilcox
2025-11-10 14:20 ` Garg, Shivank [this message]
2025-11-10 14:23 ` Lorenzo Stoakes
2025-11-10 14:28 ` Matthew Wilcox
2025-11-11 5:58 ` Garg, Shivank
2025-11-13 15:30 ` David Hildenbrand (Red Hat)
2025-11-10 14:00 ` David Hildenbrand (Red Hat)
2025-11-10 14:03 ` Matthew Wilcox
2025-11-10 14:05 ` Lorenzo Stoakes
2025-11-10 14:54 ` David Hildenbrand (Red Hat)
2025-11-13 14:21 ` kernel test robot
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