On 24.09.2021 12:33, Wei Chen wrote: >> From: Jan Beulich <jbeul...@suse.com> >> Sent: 2021年9月24日 16:56 >> >> On 23.09.2021 14:02, Wei Chen wrote: >>> --- a/xen/arch/Kconfig >>> +++ b/xen/arch/Kconfig >>> @@ -17,3 +17,14 @@ config NR_CPUS >>> For CPU cores which support Simultaneous Multi-Threading or >> similar >>> technologies, this the number of logical threads which Xen will >>> support. >>> + >>> +config NR_NUMA_NODES >>> + int "Maximum number of NUMA nodes supported" >>> + range 1 4095 >> >> How was this upper bound established? Seeing 4095 is the limit of the >> number of CPUs, do we really expect a CPU per node on such huge >> systems? And did you check that whichever involved data types and >> structures are actually suitable? I'm thinking e.g. of things like ... >> >>> --- a/xen/include/asm-x86/numa.h >>> +++ b/xen/include/asm-x86/numa.h >>> @@ -3,8 +3,6 @@ >>> >>> #include <xen/cpumask.h> >>> >>> -#define NODES_SHIFT 6 >>> - >>> typedef u8 nodeid_t; >> >> ... this. >> > > you're right, we use u8 as nodeid_t. 4095 for node number in this option > is not reasonable. Maybe a 255 upper bound is good?
I think it is, yes, but you will want to properly check. Jan
