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 E60311E0088; Wed, 4 Sep 2024 16:36:13 +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=1725467775; cv=none; b=bRalG/X+ucMtKUvV2b5+nQrBHuXeDGy0/R9EibjqII6LTo4+/rZflNOMk6/FUo1bomXXqeKPU+hqWggAtPJ3BsqZOAcPGBGuQGOyK8WmbGHUEoccs1zK1JZ8nC6x4VIwdLwTXPzf5KBYu2m4OY5QyKt3PK1pJ/byT3zcUf9OLIY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725467775; c=relaxed/simple; bh=po2G8h/VNsT+Tv0gCUS1HIxy00BOgAltSE6sYLtFebc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SrUJc875VL+60ARzHvh27HL8c+oZ49elOuyzOGbLbGJ5rJUnJh7xnySYmMJ4nV0pDsxgF/KikzfoInCdJWapynBD566Xxv+ubWZYPyQvnNrSUE3kNAugqo/yS56EhrhiFHnDav7+Pco4XW1X4n45OH2AtE7Ye490Bjz8TXyPzgA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=koOz9m7g; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="koOz9m7g" 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=6XPP+vV6bLvH9tkmOyPhy11V4N5CNl80JqIj9+LtqX4=; b=koOz9m7gqhq2M4xRkdsR9/GsDt tVV7zuMEgQbRVKtQ1MflajD6/qNDnI+XCle52x3IY5ApGwfQ7gLJtwfdqlVUcosdrQCMH1EGw0wHx e6GMdDauwQeOCLBtdeIugQDbc4lJfzxYMPqfmqCl1ga+MASOlzY8E72zPCf0Q/oxUNLcMvMYcBBjt Ftt3/Vf+HLfo//z4Y48qUnpyyPd2D3TNNvYGLk1XYv9fjcPkt5hL4ObMZOLXrZRIX5EMzAFcqEg0E wBS8YS7hMoSk2J/02jP9/WQcBiysE9vAVgVcXbFmxqTlZm36Fsg7y+WMqmz41GhiQHApQg5osCAU4 qxkrZ+cA==; Received: from willy by casper.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1slsyz-0000000189I-2azW; Wed, 04 Sep 2024 16:35:49 +0000 Date: Wed, 4 Sep 2024 17:35:49 +0100 From: Matthew Wilcox To: Suren Baghdasaryan Cc: John Hubbard , Andrew Morton , kent.overstreet@linux.dev, corbet@lwn.net, arnd@arndb.de, mcgrof@kernel.org, rppt@kernel.org, paulmck@kernel.org, thuth@redhat.com, tglx@linutronix.de, bp@alien8.de, xiongwei.song@windriver.com, ardb@kernel.org, david@redhat.com, vbabka@suse.cz, mhocko@suse.com, hannes@cmpxchg.org, roman.gushchin@linux.dev, dave@stgolabs.net, liam.howlett@oracle.com, pasha.tatashin@soleen.com, souravpanda@google.com, keescook@chromium.org, dennis@kernel.org, yuzhao@google.com, vvvvvv@google.com, rostedt@goodmis.org, iamjoonsoo.kim@lge.com, rientjes@google.com, minchan@google.com, kaleshsingh@google.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v2 6/6] alloc_tag: config to store page allocation tag refs in page flags Message-ID: References: <20240902044128.664075-1-surenb@google.com> <20240902044128.664075-7-surenb@google.com> <20240901221636.5b0af3694510482e9d9e67df@linux-foundation.org> <47c4ef47-3948-4e46-8ea5-6af747293b18@nvidia.com> Precedence: bulk X-Mailing-List: linux-modules@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 Wed, Sep 04, 2024 at 09:18:01AM -0700, Suren Baghdasaryan wrote: > I'm not sure I understand your suggestion, Matthew. We allocate a > folio and need to store a reference to the tag associated with the > code that allocated that folio. We are not operating with ranges here. > Are you suggesting to use a maple tree instead of page_ext to store > this reference? I'm saying that a folio has a physical address. So you can use a physical address as an index into a maple tree to store additional information instead of using page_ext or trying to hammer the additional information into struct page somewhere.