From: Shivank Garg <shivankg@amd.com>
To: Dev Jain <dev.jain@arm.com>,
akpm@linux-foundation.org, david@redhat.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Cc: ziy@nvidia.com, baolin.wang@linux.alibaba.com,
lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com,
npache@redhat.com, ryan.roberts@arm.com, fengwei.yin@intel.com,
bharata@amd.com,
syzbot+2b99589e33edbe9475ca@syzkaller.appspotmail.com
Subject: Re: [PATCH] mm/khugepaged: Fix race with folio splitting in hpage_collapse_scan_file()
Date: Fri, 23 May 2025 13:20:55 +0530 [thread overview]
Message-ID: <231ebbc1-2110-4d82-b4e9-5a1b1220d9c4@amd.com> (raw)
In-Reply-To: <25cb53a2-f90e-4a70-9541-2aee51d71561@arm.com>
On 5/22/2025 3:37 PM, Dev Jain wrote:
>
> On 22/05/25 3:04 pm, Shivank Garg wrote:
>> folio_mapcount() checks folio_test_large() before proceeding to
>
>
> It is not very clear in the description, where is this folio_mapcount() call present?
>
> Are you talking about is_refcount_suitable()?
Yes, The issue originates from is_refcount_suitable(), which internally relies on folio_mapcount(), which contain the race.
I'll update the description to make it clearer.
Thanks,
Shivank
prev parent reply other threads:[~2025-05-23 7:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-22 9:34 Shivank Garg
2025-05-22 10:01 ` Baolin Wang
2025-05-22 10:04 ` Dev Jain
2025-05-22 11:59 ` David Hildenbrand
2025-05-23 7:50 ` Shivank Garg
2025-05-22 10:02 ` Dev Jain
2025-05-22 10:07 ` Dev Jain
2025-05-23 7:50 ` Shivank Garg [this message]
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