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b=e6N5YwLSaG0NIXkeUTCCwISt02qYAwd45uQT2jWuzW3aERJMg1ooKCjNIjJkhaWqB Aq8bMUQwVEqC4Ug/ZIRh13kRteZIBkSX5iuPK1SNmENqrfu+yQJ+NhOAd3InmoZw4r B+++EBhlFsgKJNy+aUNO94flT3P3WjZffgVmfszZUDMgeHl0aIhUhWMxON9YV95Hfd uNmYSB0iEvKHbuLHUCkXpCUkpB1Un5w8hBa+RQZn/yvXBLQMzkv81tMCFWUG6oqKRJ 00H7DQUU2Pp2E1QwO0Hp/i+12caJwgukh9rzMIDwsuV80FbQFuG7AqIOpS8g8Cwp2o dv3NmQXTTo4zw== Message-ID: <5a4fc5ba-ab0b-4294-9577-9b5ee30b2c56@kernel.org> Date: Thu, 19 Mar 2026 12:10:36 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [mm?] kernel BUG in collapse_scan_file To: "Lorenzo Stoakes (Oracle)" Cc: Lance Yang , syzbot , willy@infradead.org, baolin.wang@linux.alibaba.com, npache@redhat.com, linux-mm@kvack.org, baohua@kernel.org, ryan.roberts@arm.com, syzkaller-bugs@googlegroups.com, dev.jain@arm.com, ziy@nvidia.com, linux-kernel@vger.kernel.org, Liam.Howlett@oracle.com, akpm@linux-foundation.org References: <69bba3c0.050a0220.227207.002b.GAE@google.com> <10e5f1d6-077d-4783-aa16-6c8b98cb9e74@lucifer.local> <8ab10631-4672-4196-b32e-7c5a01707424@kernel.org> <37b48d94-9576-4529-8576-d4ed615d4768@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: EB3F018000B X-Stat-Signature: 61mobhkf9frfar1qjym5gdfqhbojnzyy X-Rspam-User: X-HE-Tag: 1773918642-90250 X-HE-Meta: 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 OBOMnjRm STvvuVu8lJx1jcfVF23Gb0/8VesEUDcMOPBkKweyLNSiCoLrbV3dWpIk7FNBvh9y1w60NX44oCSf0eTmW66bKMqH94TAtYzTwyUuQH0L4vRaRiHj8DDdZjO9tEAxBcDqrfbMxTiebBGnapXmymSIHC6SjAqT4DrHc7vgc7h66l78F7D82TXo+gUPa7dqnIBnyFB/2qGU1fllpWdTh6JlXmcumwkLMr8aPj2ctrf4OqRNbUezRg72bTS2FwVCzTFeriZ11Jlbej6Vdf8gD2Q24ZD19Z1YgzQXDgzb1diZBwueSpVs1XAmSY+/99KLbMwvWLQMvTRMjnFBpZV7rOqs7nkY+WDvd2iJ6MOOjbYtoC+wAMBmka6vvULQgAvKDdB3QfLwBUf/2t5yRLCZ6Jnguf8A7/zrrd6+QHsxs14xTYy4XUGjqGiLl3hbBsTJ7AbGTNlBU Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: >> "This isn't the kind of thing where you can just jump in with a one line >> patch and actually be helpful, sorry." > > > Yup, so again really I don't think the kernel should take the xarray debug patch > until it is discussed and verified as correct on-list. > > See the discussion with Vlastimil. Agreed. > >> >> So I am clueless if there is a real problem there or whether it's just a >> false positive. And whether (if it's a real problem) the simple fix >> would actually be a good temporary fix ("make other bugs more likely"). >> >> I can try finding some time to look into that, but pagecache code is not >> particularly the code I'm familiar with ... > > I don't think we should waste our time on it, willy's series should be yoinked > until it can prove itself for-sure well behaved. I hear you. At the same time it has the smell of "test case fails, so let's remove the test case" vibes. Well, arguable, it's worse than a test case that fails :( I'm fine with dropping that asap. At the same time, I hope we won't lose our reminder that something possibly bad is broken upstream. -- Cheers, David