LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Michal Hocko <mhocko@kernel.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	Sachin Sant <sachinp@linux.vnet.ibm.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-mm@kvack.org, Mel Gorman <mgorman@suse.de>,
	"Kirill A. Shutemov" <kirill@shutemov.name>,
	Andrew Morton <akpm@linux-foundation.org>,
	linuxppc-dev@lists.ozlabs.org, Christopher Lameter <cl@linux.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Kirill Tkhai <ktkhai@virtuozzo.com>
Subject: Re: [PATCH 1/3] powerpc/numa: Set numa_node for all possible cpus
Date: Mon, 16 Mar 2020 10:06:52 +0100
Message-ID: <20200316090652.GC11482@dhcp22.suse.cz> (raw)
In-Reply-To: <e115048c-be38-c298-b8d1-d4b513e7d2fb@suse.cz>

On Thu 12-03-20 17:41:58, Vlastimil Babka wrote:
[...]
> with nid present in:
> N_POSSIBLE - pgdat might not exist, node_to_mem_node() must return some online

I would rather have a dummy pgdat for those. Have a look at 
$ git grep "NODE_DATA.*->" | wc -l
63

Who knows how many else we have there. I haven't looked more closely.
Besides that what is a real reason to not have pgdat ther and force all
users of a $random node from those that the platform considers possible
for special casing? Is that a memory overhead? Is that really a thing?

Somebody has suggested to tweak some of the low level routines to do the
special casing but I really have to say I do not like that. We shouldn't
use the first online node or anything like that. We should simply always
follow the topology presented by FW and of that we need to have a pgdat.
-- 
Michal Hocko
SUSE Labs

  parent reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11 11:02 [PATCH 0/3] Offline memoryless cpuless node 0 Srikar Dronamraju
2020-03-11 11:02 ` [PATCH 1/3] powerpc/numa: Set numa_node for all possible cpus Srikar Dronamraju
2020-03-11 11:57   ` Michal Hocko
2020-03-12  5:27     ` Srikar Dronamraju
2020-03-12  8:23       ` Sachin Sant
2020-03-12  9:30         ` Vlastimil Babka
2020-03-12 13:14           ` Srikar Dronamraju
2020-03-12 13:51             ` Vlastimil Babka
2020-03-12 16:13               ` Srikar Dronamraju
2020-03-12 16:41                 ` Vlastimil Babka
2020-03-13  9:47                   ` Joonsoo Kim
2020-03-13 11:04                     ` Srikar Dronamraju
2020-03-13 11:38                       ` Vlastimil Babka
2020-03-16  8:15                         ` Joonsoo Kim
2020-03-13 11:22                   ` Srikar Dronamraju
2020-03-16  9:06                   ` Michal Hocko [this message]
2020-03-17 13:44                     ` Vlastimil Babka
2020-03-17 14:01                       ` Michal Hocko
2020-03-11 11:02 ` [PATCH 2/3] powerpc/numa: Prefer node id queried from vphn Srikar Dronamraju
2020-03-11 11:02 ` [PATCH 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline Srikar Dronamraju
2020-03-15 14:20   ` Christopher Lameter
2020-03-16  8:54     ` Michal Hocko
2020-03-18  7:50       ` Srikar Dronamraju
2020-03-18 18:57       ` Christopher Lameter

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=20200316090652.GC11482@dhcp22.suse.cz \
    --to=mhocko@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=cl@linux.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=kirill@shutemov.name \
    --cc=ktkhai@virtuozzo.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mgorman@suse.de \
    --cc=sachinp@linux.vnet.ibm.com \
    --cc=srikar@linux.vnet.ibm.com \
    --cc=torvalds@linux-foundation.org \
    --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

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
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.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
	public-inbox-index lkml

Example config snippet for mirrors

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.git