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Howlett" , Vlastimil Babka , Jann Horn , Pedro Falcato , linux-fsdevel@vger.kernel.org Subject: Re: [RFC PATCH 3/6] mm: nommu: fix an issue on map request to /dev/zero Message-ID: <2026081357-shifty-magnetism-aad9@gregkh> References: <20260813063401.1786548-1-thehajime@gmail.com> <20260813063401.1786548-4-thehajime@gmail.com> <2026081355-remold-sterility-84f9@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DE4FB1C0019 X-Stat-Signature: 6shnk8sq4eydcrgyiys65fiswefmboxx X-HE-Tag: 1786630087-254752 X-HE-Meta: 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 lMxSEJkF huJDJa4tOMDlyL9bLjEhQcNwGO0oMfUnEBmZc3rHJtzJkqZnikhqFm4JDSSAN+n4UFDg34hedsupC8IdKcL2BfUhFWyAWAKvPtdzD2u8VzTlCnWSHo0bgOZmdw2MjNu5mWgJJeSWQwszDktvK3qGBwFPufsvwX9oUJcPSxxK+8y3sqQAMxv4HqYi3EgG2vFWgubgEr5pWMyTZkep/3vaTm+7+/FxWPYuxjgPazZbbs4tMdu5q44jeS9JZPsxiHxK5/L7Z+oAEMKu0dW6g3fbz9VWHorILTMDyEozjbFrJNwTf7SUowbsugcfqjDv3uHgeFwfqKIUPGVfWau7NfBun2SqHxoJjpViOi20W Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Aug 13, 2026 at 10:51:39PM +0900, Daniel Palmer wrote: > HI Lorenzo, > > On Thu, 13 Aug 2026 at 22:30, Lorenzo Stoakes (ARM) wrote: > > > One of the big problems for nommu seems to be that everyone is > > > convinced it is completely unused and totally broken. :) > > > > No, the issue is that nobody seems to do any testing or contribute any code > > aside from at least Hajime (thanks Haijme :), and possibly others (forgive me if > > I am missing people's names here!) > > > There's been situtions where nommu has been broken for a year and _nobody > > noticed_. > > > > And yet whenever nommu comes up people always seem to pop up and say how > > important it is, then mention a talk etc. > > It also broke sometime around LPC 2025, I spotted it, reported it.. > and told the people in the room at LPC for the nommu talk that it was > borken and maybe they should take a look. :) > I think I maybe even told Tazaki-san in person that it was currently > broken in the hall outside of the session. > > > Well if it's important, test it. Test the tip kernel. Report bugs. Contribute > > code. Any or all of it :) > > I rebase my 68000 tree on mainline regularly and make sure it still > works. That's how I noticed and reported the above bug. > I have a bunch of stuff that claude fable found, validated with QEMU > and then I checked on real hardware but I'm not sure how to send that > without it getting instantly marked as slop. :( I didn't say anything about slop here, and in fact, _I_ have fixed up an io_uring nommu bug in the past, using LLM tooling. I am not objecting to the use of that tool here at all, I am only commenting on the fact that this bug has been present since 2020 without anyone noticing before now, which implies a severe lack of users. Heck, the out-of-tree ia64 developers report things faster than this :) thanks, greg k-h