linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: David Hildenbrand <david@redhat.com>
To: Vishal Verma <vishal.l.verma@intel.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Oscar Salvador <osalvador@suse.de>,
	Dan Williams <dan.j.williams@intel.com>,
	Dave Jiang <dave.jiang@intel.com>
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, nvdimm@lists.linux.dev,
	linux-cxl@vger.kernel.org, Huang Ying <ying.huang@intel.com>,
	Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCH 1/3] mm/memory_hotplug: Allow an override for the memmap_on_memory param
Date: Fri, 16 Jun 2023 09:46:59 +0200	[thread overview]
Message-ID: <0ea4728a-8601-bf75-1921-bcde0818aac3@redhat.com> (raw)
In-Reply-To: <20230613-vv-kmem_memmap-v1-1-f6de9c6af2c6@intel.com>

On 16.06.23 00:00, Vishal Verma wrote:
> For memory hotplug to consider MHP_MEMMAP_ON_MEMORY behavior, the
> 'memmap_on_memory' module parameter was a hard requirement.
> 
> In preparation for the dax/kmem driver to use memmap_on_memory
> semantics, arrange for the module parameter check to be bypassed via the
> appropriate mhp_flag.
> 
> Recall that the kmem driver could contribute huge amounts of hotplugged
> memory originating from special purposes devices such as CXL memory
> expanders. In some cases memmap_on_memory may be the /only/ way this new
> memory can be hotplugged. Hence it makes sense for kmem to have a way to
> force memmap_on_memory without depending on a module param, if all the
> other conditions for it are met.

Just let the admin configure it. After all, an admin is involved in 
configuring the dax/kmem device to begin with. If add_memory() fails you 
could give a useful hint to the admin.

-- 
Cheers,

David / dhildenb



  parent reply	other threads:[~2023-06-16  7:47 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-15 22:00 [PATCH 0/3] mm: use memmap_on_memory semantics for dax/kmem Vishal Verma
2023-06-15 22:00 ` [PATCH 1/3] mm/memory_hotplug: Allow an override for the memmap_on_memory param Vishal Verma
2023-06-16  6:35   ` Huang, Ying
2023-06-16  7:46   ` David Hildenbrand [this message]
2023-06-22 13:37     ` Jonathan Cameron
2023-06-23  8:40   ` Aneesh Kumar K.V
2023-06-23 12:35     ` David Hildenbrand
2023-06-15 22:00 ` [PATCH 2/3] mm/memory_hotplug: Export symbol mhp_supports_memmap_on_memory() Vishal Verma
2023-06-16  7:47   ` David Hildenbrand
2023-06-15 22:00 ` [PATCH 3/3] dax/kmem: Always enroll hotplugged memory for memmap_on_memory Vishal Verma
2023-06-16  6:42   ` Huang, Ying
2023-06-16  7:54   ` David Hildenbrand
2023-07-11 14:30     ` Aneesh Kumar K.V
2023-07-11 15:21       ` David Hildenbrand
2023-07-13  6:45         ` Verma, Vishal L
2023-07-13  7:23           ` David Hildenbrand
2023-07-13 15:15             ` Verma, Vishal L
2023-07-13 15:23               ` David Hildenbrand
2023-07-13 15:40                 ` Verma, Vishal L
2023-07-13 15:43                   ` David Hildenbrand
2023-06-20 13:14   ` Tarun Sahu
2023-06-16  7:44 ` [PATCH 0/3] mm: use memmap_on_memory semantics for dax/kmem David Hildenbrand
2023-06-21 19:32   ` Verma, Vishal L
2023-06-22 13:55     ` David Hildenbrand
2023-07-13 19:12   ` Jeff Moyer
2023-07-14  8:35     ` David Hildenbrand
2023-07-14 13:54       ` Jeff Moyer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=0ea4728a-8601-bf75-1921-bcde0818aac3@redhat.com \
    --to=david@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=dave.jiang@intel.com \
    --cc=lenb@kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-cxl@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=nvdimm@lists.linux.dev \
    --cc=osalvador@suse.de \
    --cc=rafael@kernel.org \
    --cc=vishal.l.verma@intel.com \
    --cc=ying.huang@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).