On 13.02.2014 [14:45:49 -0800], David Rientjes wrote: > On Thu, 13 Feb 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. > > > > > > 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 <nacc@xxxxxxxxxxxxxxxxxx> > > > > ! > > > > Sorry about that Ben! > > > > > --- > > > 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. > > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > > > index 25493a0..bb2d5fe 100644 > > > --- a/arch/powerpc/Kconfig > > > +++ b/arch/powerpc/Kconfig > > > @@ -447,6 +447,9 @@ config NODES_SHIFT > > > default "4" > > > depends on NEED_MULTIPLE_NODES > > > > > > +config HAVE_MEMORYLESS_NODES > > > + def_bool NUMA > > > + > > > config ARCH_SELECT_MEMORY_MODEL > > > def_bool y > > > depends on PPC64 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>