Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Oscar Salvador <osalvador@suse.de>
To: akpm@linux-foundation.org
Cc: dan.j.williams@intel.com, david@redhat.com,
	pasha.tatashin@soleen.com, mhocko@suse.com,
	aneesh.kumar@linux.ibm.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, Oscar Salvador <osalvador@suse.de>
Subject: [PATCH 0/2] Fixes for sub-section hotplug
Date: Mon, 15 Jul 2019 10:15:47 +0200
Message-ID: <20190715081549.32577-1-osalvador@suse.de> (raw)

Hi all,

these two patches address a couple of issues I found while working on my
vmemmap-patchset.
The issues are:

	1) section_deactivate mistakenly zeroes ms->section_mem_map and then
	   tries to check whether the section is an early section, but since
	   section_mem_map might have been zeroed, we will return false
	   when it is really an early section.
	   In order to fix this, let us check whether the section is early
	   at function entry, so we do not neet check it again later.

	2) shrink_{node,zone}_span work on sub-section granularity now.
	   The problem is that deactivation of the section occurs later on
	   in sparse_remove_section, so the pfn_valid()->pfn_section_valid()
	   check will always return true.
	   The user visible effect of this is that we are always left with,
	   at least, PAGES_PER_SECTION spanned, even if we got to remove all
	   memory linked to a zone.
	   In order to fix this, decouple section_deactivate() from
	   sparse_remove_section, and let __remove_section first call
	   section_deactivate(), so then __remove_zone()->shrink_{zone,node}
	   will find the right information.

Actually, both patches could be merged in one, but I went this way to make it
more smooth.

Once this have been merged (unless there is a major controvery), I plan to send
out a patch refactoring shrink_{node,zone}_span, since right now it is a bit
messy.

Oscar Salvador (2):
  mm,sparse: Fix deactivate_section for early sections
  mm,memory_hotplug: Fix shrink_{zone,node}_span

 include/linux/memory_hotplug.h |  7 ++--
 mm/memory_hotplug.c            |  6 +++-
 mm/sparse.c                    | 76 +++++++++++++++++++++++++++++-------------
 3 files changed, 62 insertions(+), 27 deletions(-)

-- 
2.12.3


             reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-15  8:15 Oscar Salvador [this message]
2019-07-15  8:15 ` [PATCH 1/2] mm,sparse: Fix deactivate_section for early sections Oscar Salvador
2019-07-15 16:02   ` Aneesh Kumar K.V
2019-07-16  4:33   ` Dan Williams
2019-07-18 12:07   ` David Hildenbrand
2019-07-15  8:15 ` [PATCH 2/2] mm,memory_hotplug: Fix shrink_{zone,node}_span Oscar Salvador
2019-07-15 16:11   ` Aneesh Kumar K.V
2019-07-15 21:24     ` Oscar Salvador
2019-07-17  2:28       ` Dan Williams
2019-07-17  7:38         ` Oscar Salvador
2019-07-17  8:01           ` David Hildenbrand
2019-07-17  8:08             ` Oscar Salvador
2019-07-17  5:38       ` Aneesh Kumar K.V
2019-07-17  7:42         ` Oscar Salvador
2019-07-18 12:05   ` Oscar Salvador

Reply instructions:

You may reply publically 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=20190715081549.32577-1-osalvador@suse.de \
    --to=osalvador@suse.de \
    --cc=akpm@linux-foundation.org \
    --cc=aneesh.kumar@linux.ibm.com \
    --cc=dan.j.williams@intel.com \
    --cc=david@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=pasha.tatashin@soleen.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

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org
	public-inbox-index linux-mm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git