linux-kernel - Re: [PATCH v2] DAX: warn when kmem regions are truncated for memory block alignment.

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Message-ID: <67f7061681282_71fe294b2@dwillia2-xfh.jf.intel.com.notmuch>
Date: Wed, 9 Apr 2025 16:43:18 -0700
From: Dan Williams <dan.j.williams@...el.com>
To: Gregory Price <gourry@...rry.net>, <linux-cxl@...r.kernel.org>
CC: <nvdimm@...ts.linux.dev>, <linux-kernel@...r.kernel.org>,
	<kernel-team@...a.com>, <dan.j.williams@...el.com>,
	<vishal.l.verma@...el.com>, <dave.jiang@...el.com>, David Hildenbrand
	<david@...hat.com>
Subject: Re: [PATCH v2] DAX: warn when kmem regions are truncated for memory
 block alignment.

Gregory Price wrote:
> Device capacity intended for use as system ram should be aligned to the
> archite-defined memory block size or that capacity will be silently
> truncated and capacity stranded.
> 
> As hotplug dax memory becomes more prevelant, the memory block size
> alignment becomes more important for platform and device vendors to
> pay attention to - so this truncation should not be silent.
> 
> This issue is particularly relevant for CXL Dynamic Capacity devices,
> whose capacity may arrive in spec-aligned but block-misaligned chunks.
> 
> Suggested-by: David Hildenbrand <david@...hat.com>
> Suggested-by: Dan Williams <dan.j.williams@...el.com>
> Signed-off-by: Gregory Price <gourry@...rry.net>

The typo in the changelog was already noted, and this addresses all my
feedback so feel free to add:

Reviewed-by: Dan Williams <dan.j.williams@...el.com>