LKML Archive on lore.kernel.org
 help / Atom feed
From: Vlastimil Babka <vbabka@suse.cz>
To: Rashmica Gupta <rashmica.g@gmail.com>,
	toshi.kani@hpe.com, tglx@linutronix.de,
	akpm@linux-foundation.org, bp@suse.de, brijesh.singh@amd.com,
	thomas.lendacky@amd.com, jglisse@redhat.com,
	gregkh@linuxfoundation.org, baiyaowei@cmss.chinamobile.com,
	dan.j.williams@intel.com, mhocko@suse.com,
	iamjoonsoo.kim@lge.com, malat@debian.org, bhelgaas@google.com,
	osalvador@techadventures.net, yasu.isimatu@gmail.com,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	rppt@linux.vnet.ibm.com
Subject: Re: [PATCH v3] resource: Merge resources on a node when hot-adding memory
Date: Thu, 9 Aug 2018 16:30:50 +0200
Message-ID: <8fe4bac8-9ee3-de95-095d-2e915d9f366a@suse.cz> (raw)
In-Reply-To: <20180809025409.31552-1-rashmica.g@gmail.com>

On 08/09/2018 04:54 AM, Rashmica Gupta wrote:
> When hot-removing memory release_mem_region_adjustable() splits
> iomem resources if they are not the exact size of the memory being
> hot-deleted. Adding this memory back to the kernel adds a new
> resource.
> 
> Eg a node has memory 0x0 - 0xfffffffff. Offlining and hot-removing
> 1GB from 0xf40000000 results in the single resource 0x0-0xfffffffff being
> split into two resources: 0x0-0xf3fffffff and 0xf80000000-0xfffffffff.
> 
> When we hot-add the memory back we now have three resources:
> 0x0-0xf3fffffff, 0xf40000000-0xf7fffffff, and 0xf80000000-0xfffffffff.
> 
> Now if we try to remove some memory that overlaps these resources,
> like 2GB from 0xf40000000, release_mem_region_adjustable() fails as it
> expects the chunk of memory to be within the boundaries of a single
> resource.
> 
> This patch adds a function request_resource_and_merge(). This is called
> instead of request_resource_conflict() when registering a resource in
> add_memory(). It calls request_resource_conflict() and if hot-removing is
> enabled (if it isn't we won't get resource fragmentation) we attempt to
> merge contiguous resources on the node.
> 
> Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>



  reply index

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-09  2:54 Rashmica Gupta
2018-08-09 14:30 ` Vlastimil Babka [this message]
2018-08-09 15:03 ` Mike Rapoport
2018-08-10  1:12 ` Andrew Morton
2018-08-10  6:55   ` Rashmica Gupta
2018-08-10  8:28     ` Vlastimil Babka
2018-08-10 13:00     ` Michal Hocko
2018-08-10 14:25       ` Rashmica Gupta
2018-08-10 19:32         ` Oscar Salvador
2018-08-10 12:26 ` 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=8fe4bac8-9ee3-de95-095d-2e915d9f366a@suse.cz \
    --to=vbabka@suse.cz \
    --cc=akpm@linux-foundation.org \
    --cc=baiyaowei@cmss.chinamobile.com \
    --cc=bhelgaas@google.com \
    --cc=bp@suse.de \
    --cc=brijesh.singh@amd.com \
    --cc=dan.j.williams@intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=jglisse@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=malat@debian.org \
    --cc=mhocko@suse.com \
    --cc=osalvador@techadventures.net \
    --cc=rashmica.g@gmail.com \
    --cc=rppt@linux.vnet.ibm.com \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=toshi.kani@hpe.com \
    --cc=yasu.isimatu@gmail.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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

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


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


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