From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Mel Gorman <mgorman@suse.de>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Christopher Lameter <cl@linux.com>,
linuxppc-dev@lists.ozlabs.org, Vlastimil Babka <vbabka@suse.cz>
Subject: [PATCH 0/3] Offline memoryless cpuless node 0
Date: Wed, 11 Mar 2020 16:32:34 +0530 [thread overview]
Message-ID: <20200311110237.5731-1-srikar@linux.vnet.ibm.com> (raw)
Linux kernel configured with CONFIG_NUMA on a system with multiple
possible nodes, marks node 0 as online at boot. However in practice,
there are systems which have node 0 as memoryless and cpuless.
This can cause
1. numa_balancing to be enabled on systems with only one online node.
2. Existence of dummy (cpuless and memoryless) node which can confuse
users/scripts looking at output of lscpu / numactl.
This patchset wants to correct this anomaly.
This should only affect systems that have CONFIG_MEMORYLESS_NODES.
Currently there are only 2 architectures ia64 and powerpc that have this
config.
v5.6-rc4
available: 2 nodes (0,2)
node 0 cpus:
node 0 size: 0 MB
node 0 free: 0 MB
node 2 cpus: 0 1 2 3 4 5 6 7
node 2 size: 32625 MB
node 2 free: 31490 MB
node distances:
node 0 2
0: 10 20
2: 20 10
proc and sys files
------------------
/sys/devices/system/node/online: 0,2
/proc/sys/kernel/numa_balancing: 1
/sys/devices/system/node/has_cpu: 2
/sys/devices/system/node/has_memory: 2
/sys/devices/system/node/has_normal_memory: 2
/sys/devices/system/node/possible: 0-31
v5.6-rc4 + patches
------------------
available: 1 nodes (2)
node 2 cpus: 0 1 2 3 4 5 6 7
node 2 size: 32625 MB
node 2 free: 31487 MB
node distances:
node 2
2: 10
proc and sys files
------------------
/sys/devices/system/node/online: 2
/proc/sys/kernel/numa_balancing: 0
/sys/devices/system/node/has_cpu: 2
/sys/devices/system/node/has_memory: 2
/sys/devices/system/node/has_normal_memory: 2
/sys/devices/system/node/possible: 0-31
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Christopher Lameter <cl@linux.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Srikar Dronamraju (3):
powerpc/numa: Set numa_node for all possible cpus
powerpc/numa: Prefer node id queried from vphn
mm/page_alloc: Keep memoryless cpuless node 0 offline
arch/powerpc/mm/numa.c | 32 ++++++++++++++++++++++----------
mm/page_alloc.c | 4 +++-
2 files changed, 25 insertions(+), 11 deletions(-)
--
1.8.3.1
next reply other threads:[~2020-03-11 11:25 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 11:02 Srikar Dronamraju [this message]
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
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
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