On 03/28/20 at 11:31am, Hoan Tran wrote: > In NUMA layout which nodes have memory ranges that span across other nodes, > the mm driver can detect the memory node id incorrectly. > > For example, with layout below > Node 0 address: 0000 xxxx 0000 xxxx > Node 1 address: xxxx 1111 xxxx 1111 Sorry, I read this example several times, but still don't get what it means. Can it be given with real hex number address as an exmaple? I mean just using the memory layout you have seen from some systems. The change looks interesting though. > > Note: > - Memory from low to high > - 0/1: Node id > - x: Invalid memory of a node > > When mm probes the memory map, without CONFIG_NODES_SPAN_OTHER_NODES > config, mm only checks the memory validity but not the node id. > Because of that, Node 1 also detects the memory from node 0 as below > when it scans from the start address to the end address of node 1. > > Node 0 address: 0000 xxxx xxxx xxxx > Node 1 address: xxxx 1111 1111 1111 > > This layout could occur on any architecture. Most of them enables > this config by default with CONFIG_NUMA. This patch, by default, enables > CONFIG_NODES_SPAN_OTHER_NODES or uses early_pfn_in_nid() for NUMA. > > v3: > * Revise the patch description > > V2: > * Revise the patch description > > Hoan Tran (5): > mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA > powerpc: Kconfig: Remove CONFIG_NODES_SPAN_OTHER_NODES > x86: Kconfig: Remove CONFIG_NODES_SPAN_OTHER_NODES > sparc: Kconfig: Remove CONFIG_NODES_SPAN_OTHER_NODES > s390: Kconfig: Remove CONFIG_NODES_SPAN_OTHER_NODES > > arch/powerpc/Kconfig | 9 --------- > arch/s390/Kconfig | 8 -------- > arch/sparc/Kconfig | 9 --------- > arch/x86/Kconfig | 9 --------- > mm/page_alloc.c | 2 +- > 5 files changed, 1 insertion(+), 36 deletions(-) > > -- > 1.8.3.1 > >
