From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 21F6522339 for ; Thu, 5 Feb 2026 04:17:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770265057; cv=none; b=YMIIVsbmhcLAsCYQmjytpyJQAIDqK0/htJ/PJfpsO2f8a9ahOr4Gl9P8lqCOCk2HGIq2XgZENTKBwvEMnYM43eUqeDD+9rGjZ+AF4qxAC/QYvAJUPJAkKVSlQaJ3q0UVWezglkCsM6IHOWiT6WBLgyqZcrLVkVjMPKCQdlQldzE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770265057; c=relaxed/simple; bh=D3OiXtlFSYoTYlFGI085rOdYg222RaIdB8IDY6VrOOo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bcFkM42Ku7ULX092BTBF3sLcTXN9am/kU7Kb/G3GD/4TgkJrS7rm17woZQeiRbS8XcYCP8BjNffke5zKtHmvmdU7rGJRoiMiVeDDJetAUft39Y0vyX073v7s+a7spkYZH3nsNXvUIK0rs2DDvzCcDtnCmTIxVRqvsmirJCFWKeo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=T5Ngi+c7; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="T5Ngi+c7" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Pf15hugocmsBA1n+k7JdTpjyzGH93mUVvu7n/6Ol7+Y=; b=T5Ngi+c7LeRLgjSaxA3vtckg9A 9jUrICdhn7T/tw4zJksOJWYF7LdWvpPZVYzPOLA0Q9RKiSe9bb7GJoylJa1BUijxUZBtdPMOjwHMz F3B+OIUjgFGtkQlXJ/ZlNv7kJ+/y+QMRIZFs0zDlifSyeDldH8OwQY1K9GFxD+qtlmPrfVIWBUcSJ x0FNxg4StrlPnALcFtZBqIUhu1qcm17t29082HqOIFlZzRkXm/rk22h+Y2cNTt8OUZ0ANn0NvDUDj gfCJmLmKzzVuOquCvHpjLSZyD8uJjfkB5VydNjvSRkJNj5fGYU51evnMQ8k5JDZi8VyKlzKwIS81X QtXsBp3A==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vnqnv-000000035OP-35v2; Thu, 05 Feb 2026 04:17:19 +0000 Date: Thu, 5 Feb 2026 04:17:19 +0000 From: Matthew Wilcox To: Usama Arif Cc: Zi Yan , Kiryl Shutsemau , lorenzo.stoakes@oracle.com, Andrew Morton , David Hildenbrand , linux-mm@kvack.org, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, vbabka@suse.cz, lance.yang@linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [RFC 01/12] mm: add PUD THP ptdesc and rmap support Message-ID: References: <20260202005451.774496-1-usamaarif642@gmail.com> <20260202005451.774496-2-usamaarif642@gmail.com> <63D23D5F-AF35-4199-B52E-DFFC16DFDF91@nvidia.com> <05d5918f-b61b-4091-b8c6-20eebfffc3c4@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <05d5918f-b61b-4091-b8c6-20eebfffc3c4@gmail.com> On Tue, Feb 03, 2026 at 02:07:25PM -0800, Usama Arif wrote: > Ah I should have looked at your patches more! I started working by just using lru > and was using list_add/list_del which was ofcourse corrupting the list and took me > way more time than I would like to admit to debug what was going on! The diagrams > in your 2nd link are really useful. I ended up drawing by hand those to debug > the corruption issue. I will point to that link in the next series :) > > How about something like the below diff over this patch? (Not included the comment > changes that I will make everywhere) Why are you even talking about "the next series"? The approach is wrong. You need to put this POC aside and solve the problems that you've bypassed to create this POC.