From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9A6C147AF42 for ; Thu, 13 Aug 2026 14:08:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786630088; cv=none; b=h5EKFQWRxmSNJllwrHz9AJ7xEQ03vrBjg5n6YufMCpGlswp3gusTv2ERYhtP/s5y6HixACIPuAhQhf3YZyzR2LOnGrYysG/LaNOcrpVdVoFSA4uhC3/V7KIZV8FIW3NOYng1lr8FL8R9ds6ZRvecXOEAkMzZgeS6JL4bHdEDg30= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786630088; c=relaxed/simple; bh=RJSJZWefU1czaGTh4s7+rDOpSEJVL4LSUK3ee4wu4RQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=l1Bn+WRhJ+Az+O9Wr10YBewfrHAAYTFWxj78csOkqLcd1kOE/YaO0pZi7vDqPIHtzM03bnr7620fqV4UmbceDGsa0XxLVDjuvc5csLUhCdOT4AQeREI0AfSShSVO3u338EqJ1muA49cZ7h5tZXFTU7WvYD7psVPTqLTgKTHIw7A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Jo4EJJT7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Jo4EJJT7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B4F61F000E9; Thu, 13 Aug 2026 14:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786630087; bh=ILJpY2zOeVhfdUYo8J0UMIm0dyJAM7pQkJ2oTlpZAH0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Jo4EJJT7ekasvk1jXDjxSIOfXcu2sd8vYPAdDUba8IOdeWRPVJ3DS1M7aJFDnpvIi VRNE57tRh+FU7UU+Ga7XtJ8diU/77qaBeR0atIA56y2YZhgczBuDXh6sUdM3LXB+qq p/JFPbe9ULhEk3nsdx4C7Sr5/JsXFLZeWBiSFqv8= Date: Thu, 13 Aug 2026 23:06:33 +0900 From: Greg Kroah-Hartman To: Daniel Palmer Cc: "Lorenzo Stoakes (ARM)" , Hajime Tazaki , linux-mm@kvack.org, geert@linux-m68k.org, Arnd Bergmann , "Matthew Wilcox (Oracle)" , Jan Kara , Andrew Morton , "Liam R. 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> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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