Anton Blanchard found an issue with an LPAR that had no memory in Node
0. Christoph Lameter recommended, as one possible solution, to use
numa_mem_id() for locality of the nearest memory node-wise. However,
numa_mem_id() [and the other related APIs] are only useful if
CONFIG_HAVE_MEMORYLESS_NODES is set. This is only the case for ia64
currently, but clearly we can have memoryless nodes on ppc64. Add the
Kconfig option and define it to be the same value as CONFIG_NUMA.
On the LPAR in question, which was very inefficiently using slabs, this
took the slab consumption at boot from roughly 7GB to roughly 4GB.
---
Ben, the only question I have wrt this change is if it's appropriate to
change it for all powerpc configs (that have NUMA on)?
From: Christoph Lameter <hidden> Date: 2014-01-29 15:55:50
On Tue, 28 Jan 2014, Nishanth Aravamudan wrote:
Anton Blanchard found an issue with an LPAR that had no memory in Node
0. Christoph Lameter recommended, as one possible solution, to use
numa_mem_id() for locality of the nearest memory node-wise. However,
numa_mem_id() [and the other related APIs] are only useful if
CONFIG_HAVE_MEMORYLESS_NODES is set. This is only the case for ia64
currently, but clearly we can have memoryless nodes on ppc64. Add the
Kconfig option and define it to be the same value as CONFIG_NUMA.
Well this is trivial but if you need encouragement:
Reviewed-by: Christoph Lameter <redacted>
On 28.01.2014 [10:34:57 -0800], Nishanth Aravamudan wrote:
Anton Blanchard found an issue with an LPAR that had no memory in Node
0. Christoph Lameter recommended, as one possible solution, to use
numa_mem_id() for locality of the nearest memory node-wise. However,
numa_mem_id() [and the other related APIs] are only useful if
CONFIG_HAVE_MEMORYLESS_NODES is set. This is only the case for ia64
currently, but clearly we can have memoryless nodes on ppc64. Add the
Kconfig option and define it to be the same value as CONFIG_NUMA.
On the LPAR in question, which was very inefficiently using slabs, this
took the slab consumption at boot from roughly 7GB to roughly 4GB.
Err, this should have been
Signed-off-by: Nishanth Aravamudan <redacted>
!
Sorry about that Ben!
quoted hunk
---
Ben, the only question I have wrt this change is if it's appropriate to
change it for all powerpc configs (that have NUMA on)?
From: David Rientjes <rientjes@google.com> Date: 2014-02-13 22:51:47
On Thu, 13 Feb 2014, Nishanth Aravamudan wrote:
quoted
Anton Blanchard found an issue with an LPAR that had no memory in Node
0. Christoph Lameter recommended, as one possible solution, to use
numa_mem_id() for locality of the nearest memory node-wise. However,
numa_mem_id() [and the other related APIs] are only useful if
CONFIG_HAVE_MEMORYLESS_NODES is set. This is only the case for ia64
currently, but clearly we can have memoryless nodes on ppc64. Add the
Kconfig option and define it to be the same value as CONFIG_NUMA.
On the LPAR in question, which was very inefficiently using slabs, this
took the slab consumption at boot from roughly 7GB to roughly 4GB.
Err, this should have been
Signed-off-by: Nishanth Aravamudan <redacted>
!
Sorry about that Ben!
quoted
---
Ben, the only question I have wrt this change is if it's appropriate to
change it for all powerpc configs (that have NUMA on)?
I'm suspecting that Ben will request that the proper set_numa_mem() calls
are done for ppc init to make this actually do anything other than return
numa_mem_id() == numa_node_id().
On 13.02.2014 [14:45:49 -0800], David Rientjes wrote:
On Thu, 13 Feb 2014, Nishanth Aravamudan wrote:
quoted
quoted
Anton Blanchard found an issue with an LPAR that had no memory in Node
0. Christoph Lameter recommended, as one possible solution, to use
numa_mem_id() for locality of the nearest memory node-wise. However,
numa_mem_id() [and the other related APIs] are only useful if
CONFIG_HAVE_MEMORYLESS_NODES is set. This is only the case for ia64
currently, but clearly we can have memoryless nodes on ppc64. Add the
Kconfig option and define it to be the same value as CONFIG_NUMA.
On the LPAR in question, which was very inefficiently using slabs, this
took the slab consumption at boot from roughly 7GB to roughly 4GB.
Err, this should have been
Signed-off-by: Nishanth Aravamudan <redacted>
!
Sorry about that Ben!
quoted
---
Ben, the only question I have wrt this change is if it's appropriate to
change it for all powerpc configs (that have NUMA on)?
I'm suspecting that Ben will request that the proper set_numa_mem() calls
are done for ppc init to make this actually do anything other than return
numa_mem_id() == numa_node_id().
You're right, thanks for pointing this out. I could have sworn that in
my previous debugging I saw proper NUMA information, but perhaps it was
just correct based upon the system configuration.