Gregory Price <gregory.price@xxxxxxxxxxxx> writes: > On Fri, Jan 05, 2024 at 02:51:40PM +0800, Huang, Ying wrote: >> > >> > So we're talking ~1MB for 1024 threads with mempolicies to avoid error >> > conditions mid-page-allocation and to reduce the cost associated with >> > applying weighted interleave. >> >> Think about this again. Why do we need weights array on stack? I think >> this is used to keep weights consistent. If so, we don't need weights >> array on stack. Just use RCU to access global weights array. >> > > From the bulk allocation code: > > __alloc_pages_bulk(gfp, node, NULL, node_pages, NULL, page_array); > > This function can block. You cannot block during an RCU read context. Yes. You are right. For __alloc_pages_bulk(), it should be OK to allocate the weights array. For weighted_interleave_nid(), we can use RCU to avoid memory allocation in relative fast code path. BTW, we can use nr_node_ids instead of MAX_NUMNODES if applicable. -- Best Regards, Huang, Ying
