From c6c21c31d0d8b200d448b5edc1e2d47991b3df5a Mon Sep 17 00:00:00 2001 From: Gang Li Date: Thu, 22 Feb 2024 22:04:20 +0800 Subject: hugetlb: parallelize 2M hugetlb allocation and initialization By distributing both the allocation and the initialization tasks across multiple threads, the initialization of 2M hugetlb will be faster, thereby improving the boot speed. Here are some test results: test case no patch(ms) patched(ms) saved ------------------- -------------- ------------- -------- 256c2T(4 node) 2M 3336 1051 68.52% 128c1T(2 node) 2M 1943 716 63.15% Link: https://lkml.kernel.org/r/20240222140422.393911-8-gang.li@linux.dev Signed-off-by: Gang Li Tested-by: David Rientjes Reviewed-by: Muchun Song Cc: Alexey Dobriyan Cc: Daniel Jordan Cc: David Hildenbrand Cc: Jane Chu Cc: Mike Kravetz Cc: Paul E. McKenney Cc: Randy Dunlap Cc: Steffen Klassert Cc: Tim Chen Signed-off-by: Andrew Morton --- mm/hugetlb.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 56 insertions(+), 17 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1c8274f8650e..9934ed8aad68 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -3510,6 +3511,30 @@ static void __init hugetlb_hstate_alloc_pages_errcheck(unsigned long allocated, } } +static void __init hugetlb_pages_alloc_boot_node(unsigned long start, unsigned long end, void *arg) +{ + struct hstate *h = (struct hstate *)arg; + int i, num = end - start; + nodemask_t node_alloc_noretry; + LIST_HEAD(folio_list); + int next_node = first_online_node; + + /* Bit mask controlling how hard we retry per-node allocations.*/ + nodes_clear(node_alloc_noretry); + + for (i = 0; i < num; ++i) { + struct folio *folio = alloc_pool_huge_folio(h, &node_states[N_MEMORY], + &node_alloc_noretry, &next_node); + if (!folio) + break; + + list_move(&folio->lru, &folio_list); + cond_resched(); + } + + prep_and_add_allocated_folios(h, &folio_list); +} + static unsigned long __init hugetlb_gigantic_pages_alloc_boot(struct hstate *h) { unsigned long i; @@ -3525,26 +3550,40 @@ static unsigned long __init hugetlb_gigantic_pages_alloc_boot(struct hstate *h) static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h) { - unsigned long i; - struct folio *folio; - LIST_HEAD(folio_list); - nodemask_t node_alloc_noretry; - - /* Bit mask controlling how hard we retry per-node allocations.*/ - nodes_clear(node_alloc_noretry); + struct padata_mt_job job = { + .fn_arg = h, + .align = 1, + .numa_aware = true + }; - for (i = 0; i < h->max_huge_pages; ++i) { - folio = alloc_pool_huge_folio(h, &node_states[N_MEMORY], - &node_alloc_noretry); - if (!folio) - break; - list_add(&folio->lru, &folio_list); - cond_resched(); - } + job.thread_fn = hugetlb_pages_alloc_boot_node; + job.start = 0; + job.size = h->max_huge_pages; - prep_and_add_allocated_folios(h, &folio_list); + /* + * job.max_threads is twice the num_node_state(N_MEMORY), + * + * Tests below indicate that a multiplier of 2 significantly improves + * performance, and although larger values also provide improvements, + * the gains are marginal. + * + * Therefore, choosing 2 as the multiplier strikes a good balance between + * enhancing parallel processing capabilities and maintaining efficient + * resource management. + * + * +------------+-------+-------+-------+-------+-------+ + * | multiplier | 1 | 2 | 3 | 4 | 5 | + * +------------+-------+-------+-------+-------+-------+ + * | 256G 2node | 358ms | 215ms | 157ms | 134ms | 126ms | + * | 2T 4node | 979ms | 679ms | 543ms | 489ms | 481ms | + * | 50G 2node | 71ms | 44ms | 37ms | 30ms | 31ms | + * +------------+-------+-------+-------+-------+-------+ + */ + job.max_threads = num_node_state(N_MEMORY) * 2; + job.min_chunk = h->max_huge_pages / num_node_state(N_MEMORY) / 2; + padata_do_multithreaded(&job); - return i; + return h->nr_huge_pages; } /* -- cgit v1.2.3