On Tue, Oct 25, 2016 at 10:59:18AM +0800, Zhen Lei wrote: > Some numa nodes may have no memory. For example: > 1) a node has no memory bank plugged. > 2) a node has no memory bank slots. > > To ensure percpu variable areas and numa control blocks of the > memoryless numa nodes to be allocated from the nearest available node to > improve performance, defined node_distance_ready. And make its value to be > true immediately after node distances have been initialized. > > Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> > --- > arch/arm64/Kconfig | 4 ++++ > arch/arm64/include/asm/numa.h | 3 +++ > arch/arm64/mm/numa.c | 6 +++++- > 3 files changed, 12 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 30398db..648dd13 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -609,6 +609,10 @@ config NEED_PER_CPU_EMBED_FIRST_CHUNK > def_bool y > depends on NUMA > > +config HAVE_MEMORYLESS_NODES > + def_bool y > + depends on NUMA Given that patch 1 and the associated node_distance_ready stuff is all an unqualified performance optimisation, is there any merit in just enabling HAVE_MEMORYLESS_NODES in Kconfig and then optimising things as a separate series when you have numbers to back it up? Will -- 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>