All of lore.kernel.org
 help / color / mirror / Atom feed
From: Oscar Salvador <osalvador@suse.de>
To: Michal Hocko <mhocko@suse.com>
Cc: david@redhat.com, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@soleen.com
Subject: Re: [RFC PATCH v2 3/4] mm,memory_hotplug: Add mhp_supports_memmap_on_memory
Date: Mon, 30 Nov 2020 09:50:22 +0100	[thread overview]
Message-ID: <20201130085018.GA3825@linux> (raw)
In-Reply-To: <20201127150253.GU31550@dhcp22.suse.cz>

On Fri, Nov 27, 2020 at 04:02:53PM +0100, Michal Hocko wrote:
> It should also require a tunable (kernel parameter for now but maybe we
> will need a more fine grained control later) to enable this explicitly.
> Earlier discussions have pointed out that allocating vmemmap from each
> section can lead to a sparse memory unsuitable for very large pages.
> So I believe this should be an opt in.

Yeah, I already had that in mind, just did not get to implement it in this RFC
yet as I was more focused on the implementation per se.
I thought about a tunable in /sys/device/system/memory/[file], but a kernel
command line boot option would also work and for the first implementation
would be less for a hassel.

> Also is there any reason why this cannot be a preparatory patch for the
> actual implementation? It would look more natural that way to me.

I guess you are right, will re-order it in a future submission.

-- 
Oscar Salvador
SUSE L3


  reply	other threads:[~2020-11-30  8:50 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-25 11:20 [RFC PATCH v2 0/4] Allocate memmap from hotadded memory (per device) Oscar Salvador
2020-11-25 11:20 ` [RFC PATCH v2 1/4] mm,memory_hotplug: Introduce MHP_MEMMAP_ON_MEMORY Oscar Salvador
2020-11-27 14:59   ` Michal Hocko
2020-11-25 11:20 ` [RFC PATCH v2 2/4] mm,memory_hotplug: Allocate memmap from the added memory range Oscar Salvador
2020-11-27 15:15   ` Michal Hocko
2020-11-30  9:12     ` Oscar Salvador
2020-11-25 11:20 ` [RFC PATCH v2 3/4] mm,memory_hotplug: Add mhp_supports_memmap_on_memory Oscar Salvador
2020-11-25 13:18   ` [RFC PATCH v2 3/4] mm, memory_hotplug: " kernel test robot
2020-11-25 13:20   ` kernel test robot
2020-11-27 15:02   ` [RFC PATCH v2 3/4] mm,memory_hotplug: " Michal Hocko
2020-11-30  8:50     ` Oscar Salvador [this message]
2020-11-25 11:20 ` [RFC PATCH v2 4/4] mm,memory_hotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Oscar Salvador
2020-11-27 11:55   ` Oscar Salvador

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=20201130085018.GA3825@linux \
    --to=osalvador@suse.de \
    --cc=david@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=pasha.tatashin@soleen.com \
    --cc=vbabka@suse.cz \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.