On Thu, Jan 22, 2026 at 03:21:12PM -0800, Andrew Morton wrote: > On Tue, 20 Jan 2026 17:59:11 +0000 Evangelos Petrongonas <[email protected]> > wrote: > > > kho_reserve_scratch() iterates over all online NUMA nodes to allocate > > per-node scratch memory. On systems with memoryless NUMA nodes (nodes > > that have CPUs but no memory), memblock_alloc_range_nid() fails because > > there is no memory available on that node. This causes KHO initialization > > to fail and kho_enable to be set to false. > > > > Some ARM64 systems have NUMA topologies where certain nodes contain only > > CPUs without any associated memory. These configurations are valid and > > should not prevent KHO from functioning. > > > > Fix this by only counting nodes that have memory (N_MEMORY state) and > > skip memoryless nodes in the per-node scratch allocation loop. > > > > So kho is unusable on such machines. > > Should we backport this? I'm thinking > > Fixes: 3dc92c311498 ("kexec: add Kexec HandOver (KHO) generation helpers").
It's only for v6.18, but sure, why not. -- Sincerely yours, Mike.
