From: "Mike Rapoport (Microsoft)" deferred_init_memmap() loops over free memory ranges and creates a padata_mt_job for every free range that intersects with the zone being initialized. padata_do_multithreaded() then splits every such range to several chunks and runs a thread that initializes struct pages in that chunk using deferred_init_memmap_chunk(). The number of threads is limited by amount of the CPUs on the node (or 1 for memoryless nodes). Looping through free memory ranges is then repeated in deferred_init_memmap_chunk() first to find the first range that should be initialized and then to traverse the ranges until the end of the chunk is reached. Remove the loop over free memory regions in deferred_init_memmap() and pass the entire zone to padata_do_multithreaded() so that it will be divided to several chunks by the parallelization code. Reviewed-by: David Hildenbrand Reviewed-by: Wei Yang Link: https://lore.kernel.org/r/20250818064615.505641-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) --- mm/mm_init.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/mm/mm_init.c b/mm/mm_init.c index e73f313dc375..57b256ea9e6c 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2179,12 +2179,10 @@ static int __init deferred_init_memmap(void *data) { pg_data_t *pgdat = data; const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); - unsigned long spfn = 0, epfn = 0; - unsigned long first_init_pfn, flags; + int max_threads = deferred_page_init_max_threads(cpumask); + unsigned long first_init_pfn, last_pfn, flags; unsigned long start = jiffies; struct zone *zone; - int max_threads; - u64 i = 0; /* Bind memory initialisation thread to a local node if possible */ if (!cpumask_empty(cpumask)) @@ -2212,24 +2210,20 @@ static int __init deferred_init_memmap(void *data) /* Only the highest zone is deferred */ zone = pgdat->node_zones + pgdat->nr_zones - 1; - - max_threads = deferred_page_init_max_threads(cpumask); - - while (deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn, first_init_pfn)) { - first_init_pfn = ALIGN(epfn, PAGES_PER_SECTION); - struct padata_mt_job job = { - .thread_fn = deferred_init_memmap_job, - .fn_arg = zone, - .start = spfn, - .size = first_init_pfn - spfn, - .align = PAGES_PER_SECTION, - .min_chunk = PAGES_PER_SECTION, - .max_threads = max_threads, - .numa_aware = false, - }; - - padata_do_multithreaded(&job); - } + last_pfn = SECTION_ALIGN_UP(zone_end_pfn(zone)); + + struct padata_mt_job job = { + .thread_fn = deferred_init_memmap_job, + .fn_arg = zone, + .start = first_init_pfn, + .size = last_pfn - first_init_pfn, + .align = PAGES_PER_SECTION, + .min_chunk = PAGES_PER_SECTION, + .max_threads = max_threads, + .numa_aware = false, + }; + + padata_do_multithreaded(&job); /* Sanity check that the next zone really is unpopulated */ WARN_ON(pgdat->nr_zones < MAX_NR_ZONES && populated_zone(++zone)); -- 2.50.1