From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5D9C8386C31; Mon, 27 Apr 2026 12:38:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777293526; cv=none; b=V3cuk6Hx01KKMu2CyrDn7G2Zn47U9NItUSLJvz4nN6NK65MN3ODSSSIU8i585iLDbsRaxRBbc3caxZsFxpiZQZZ9YM3lJrH8dSEDW2gchwgu913BfPizwcyz564rYWl03p0pip0cTkusDVUTaD8LlFrIbysycy6nOTp2+MUB4Qc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777293526; c=relaxed/simple; bh=WCOiWJ33H12Gt9WXtMejTD0F71tWc2TIJy7Wuf1KJNk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gYqsZ9ahy5loz8nFx4XEMa2HgrskG+qdFuHRn8DRzXrAhB4OFZk+uU0VaCFMWoqMBRP3cyZKxPUDtfTtRVJXDtz0GekXRfSk40lR8W5yup0CaM2xWeFzlxrd9G11N/Osl14hF5lI8B0h/YuqtuSAFUmArAa0Z/Vl74t7iD25MAE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XZ3yZrMn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XZ3yZrMn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 023ACC19425; Mon, 27 Apr 2026 12:38:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777293526; bh=WCOiWJ33H12Gt9WXtMejTD0F71tWc2TIJy7Wuf1KJNk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XZ3yZrMnToibUBPmSg2kmBm8Bwx+xjBrieLlQ4QIj3Hjjrxaob4B88GjoxsHY5UEY M8W8err9/EUhALKBTfGnRq9KdE00Y0Cjp+GSsOONCnj1rSo4D2Py54L33nmH5aRqfK BZ8F72ojyZZXGzdp94ZawHeczLhHGgUUtmhKQrm/GHJIR6NDkF6JmUemSrkV2kM89C eem75ThSG+TYpL5eU62ebSNHaHx+53Wk+TBKK9naXdWISIqwUFRD7B95HGKf+MMiWq 7L+CZVeh0BCqaMPMjnursVny/DCAle92ayIrHd0bkb9Tnk4UobkrALNJlvQpbm0aYE Z1T0BIvrzEPtw== Date: Mon, 27 Apr 2026 13:38:33 +0100 From: Jonathan Cameron To: Ira Weiny Cc: John Groves , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , "Vishal Verma" , "Dan Williams" , John Groves , Fan Ni , Anisa Su , Shiju Jose , Robert Richter , "linux-cxl@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "dev.srinivasulu@gmail.com" , "arramesh@micron.com" , "ajayjoshi@micron.com" Subject: Re: [RFC PATCH 1/4] cxl/extent: Promote cxlr_dax->region_extent to an xarray Message-ID: <20260427133833.61b9cbca@jic23-huawei> In-Reply-To: <69ebe836a8ea_bde13100d@iweiny-mobl.notmuch> References: <0100019dbcc13648-596853f3-0083-46e0-b654-396eedd657cb-000000@email.amazonses.com> <20260423235158.3732476-1-john@jagalactic.com> <0100019dbcc1f7da-e3c5b4b3-6505-4dc6-9952-70a4676cbdb6-000000@email.amazonses.com> <69ebe836a8ea_bde13100d@iweiny-mobl.notmuch> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit > Look at the diagrams in this presentation: > > https://lpc.events/event/18/contributions/1826/attachments/1435/3335/LPC2024_CXL_DCD-v2.pdf > > 'DAX dev 1' covers memory from Extent A and Extent B. What yall will want > to do is ensure that the region extents which get surfaced are ordered > based on the sequence number _when_ _the_ _dax_ _device_ is created. The > order they come into the host does not really matter. Although yea the > spec has a bunch of rules... so whatever, follow those. But it is the > dax device which groups the extents into a contiguous HPA range and maps On this bit, HPA? Why would extents be contiguous in HPA? Contiguous in the DAX device mapping sure, but not HPA. > those ranges through struct dev_dax->ranges.