Re: Tomas Vondra > Thanks! Pushed, with both adjustments (link to kernel thread, adding the > commit hash).
The PG18 Debian package is still carrying the contrib complement of this patch (see attachment). Should that be addressed before 18.0? Christoph
Work around a Linux bug in move_pages In 32-bit mode on 64-bit kernels, move_pages() does not correctly advance to the next chunk. Work around by not asking for more than 16 pages at once so move_pages() internal loop is not executed more than once. https://www.postgresql.org/message-id/flat/a3a4fe3d-1a80-4e03-aa8e-150ee15f6c35%40vondra.me#6abe7eaa802b5b07bb70cc3229e63a9f https://marc.info/?l=linux-mm&m=175077821909222&w=2 --- a/contrib/pg_buffercache/pg_buffercache_pages.c +++ b/contrib/pg_buffercache/pg_buffercache_pages.c @@ -390,8 +390,15 @@ pg_buffercache_numa_pages(PG_FUNCTION_AR memset(os_page_status, 0xff, sizeof(int) * os_page_count); /* Query NUMA status for all the pointers */ - if (pg_numa_query_pages(0, os_page_count, os_page_ptrs, os_page_status) == -1) - elog(ERROR, "failed NUMA pages inquiry: %m"); +#define NUMA_QUERY_CHUNK_SIZE 16 /* has to be <= DO_PAGES_STAT_CHUNK_NR (do_pages_stat())*/ + for (uint64 chunk_start = 0; chunk_start < os_page_count; chunk_start += NUMA_QUERY_CHUNK_SIZE) { + uint64 chunk_size = Min(NUMA_QUERY_CHUNK_SIZE, os_page_count - chunk_start); + + if (pg_numa_query_pages(0, chunk_size, &os_page_ptrs[chunk_start], + &os_page_status[chunk_start]) == -1) + elog(ERROR, "failed NUMA pages inquiry status: %m"); + } +#undef NUMA_QUERY_CHUNK_SIZE /* Initialize the multi-call context, load entries about buffers */ --- a/src/backend/storage/ipc/shmem.c +++ b/src/backend/storage/ipc/shmem.c @@ -689,8 +689,15 @@ pg_get_shmem_allocations_numa(PG_FUNCTIO CHECK_FOR_INTERRUPTS(); } - if (pg_numa_query_pages(0, shm_ent_page_count, page_ptrs, pages_status) == -1) - elog(ERROR, "failed NUMA pages inquiry status: %m"); +#define NUMA_QUERY_CHUNK_SIZE 16 /* has to be <= DO_PAGES_STAT_CHUNK_NR (do_pages_stat())*/ + for (uint64 chunk_start = 0; chunk_start < shm_ent_page_count; chunk_start += NUMA_QUERY_CHUNK_SIZE) { + uint64 chunk_size = Min(NUMA_QUERY_CHUNK_SIZE, shm_ent_page_count - chunk_start); + + if (pg_numa_query_pages(0, chunk_size, &page_ptrs[chunk_start], + &pages_status[chunk_start]) == -1) + elog(ERROR, "failed NUMA pages inquiry status: %m"); + } +#undef NUMA_QUERY_CHUNK_SIZE /* Count number of NUMA nodes used for this shared memory entry */ memset(nodes, 0, sizeof(Size) * (max_nodes + 1));
