The patch titled Subject: hugetlb: parallelize 1G hugetlb initialization has been added to the -mm mm-unstable branch. Its filename is hugetlb-parallelize-1g-hugetlb-initialization.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-parallelize-1g-hugetlb-initialization.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Gang Li <gang.li@xxxxxxxxx> Subject: hugetlb: parallelize 1G hugetlb initialization Date: Thu, 22 Feb 2024 22:04:21 +0800 Optimizing the initialization speed of 1G huge pages through parallelization. 1G hugetlbs are allocated from bootmem, a process that is already very fast and does not currently require optimization. Therefore, we focus on parallelizing only the initialization phase in `gather_bootmem_prealloc`. Here are some test results: test case no patch(ms) patched(ms) saved ------------------- -------------- ------------- -------- 256c2T(4 node) 1G 4745 2024 57.34% 128c1T(2 node) 1G 3358 1712 49.02% 12T 1G 77000 18300 76.23% Link: https://lkml.kernel.org/r/20240222140422.393911-9-gang.li@xxxxxxxxx Signed-off-by: Gang Li <ligang.bdlg@xxxxxxxxxxxxx> Tested-by: David Rientjes <rientjes@xxxxxxxxxx> Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/powerpc/mm/hugetlbpage.c | 2 - include/linux/hugetlb.h | 2 - mm/hugetlb.c | 51 ++++++++++++++++++++++++++------ 3 files changed, 45 insertions(+), 10 deletions(-) --- a/arch/powerpc/mm/hugetlbpage.c~hugetlb-parallelize-1g-hugetlb-initialization +++ a/arch/powerpc/mm/hugetlbpage.c @@ -226,7 +226,7 @@ static int __init pseries_alloc_bootmem_ return 0; m = phys_to_virt(gpage_freearray[--nr_gpages]); gpage_freearray[nr_gpages] = 0; - list_add(&m->list, &huge_boot_pages); + list_add(&m->list, &huge_boot_pages[0]); m->hstate = hstate; return 1; } --- a/include/linux/hugetlb.h~hugetlb-parallelize-1g-hugetlb-initialization +++ a/include/linux/hugetlb.h @@ -178,7 +178,7 @@ pte_t *huge_pmd_share(struct mm_struct * struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage); extern int sysctl_hugetlb_shm_group; -extern struct list_head huge_boot_pages; +extern struct list_head huge_boot_pages[MAX_NUMNODES]; /* arch callbacks */ --- a/mm/hugetlb.c~hugetlb-parallelize-1g-hugetlb-initialization +++ a/mm/hugetlb.c @@ -69,7 +69,7 @@ static bool hugetlb_cma_folio(struct fol #endif static unsigned long hugetlb_cma_size __initdata; -__initdata LIST_HEAD(huge_boot_pages); +__initdata struct list_head huge_boot_pages[MAX_NUMNODES]; /* for command line parsing */ static struct hstate * __initdata parsed_hstate; @@ -3301,7 +3301,7 @@ int alloc_bootmem_huge_page(struct hstat int __alloc_bootmem_huge_page(struct hstate *h, int nid) { struct huge_bootmem_page *m = NULL; /* initialize for clang */ - int nr_nodes, node; + int nr_nodes, node = nid; /* do node specific alloc */ if (nid != NUMA_NO_NODE) { @@ -3339,7 +3339,7 @@ found: huge_page_size(h) - PAGE_SIZE); /* Put them into a private list first because mem_map is not up yet */ INIT_LIST_HEAD(&m->list); - list_add(&m->list, &huge_boot_pages); + list_add(&m->list, &huge_boot_pages[node]); m->hstate = h; return 1; } @@ -3390,8 +3390,6 @@ static void __init prep_and_add_bootmem_ /* Send list for bulk vmemmap optimization processing */ hugetlb_vmemmap_optimize_folios(h, folio_list); - /* Add all new pool pages to free lists in one lock cycle */ - spin_lock_irqsave(&hugetlb_lock, flags); list_for_each_entry_safe(folio, tmp_f, folio_list, lru) { if (!folio_test_hugetlb_vmemmap_optimized(folio)) { /* @@ -3404,23 +3402,25 @@ static void __init prep_and_add_bootmem_ HUGETLB_VMEMMAP_RESERVE_PAGES, pages_per_huge_page(h)); } + /* Subdivide locks to achieve better parallel performance */ + spin_lock_irqsave(&hugetlb_lock, flags); __prep_account_new_huge_page(h, folio_nid(folio)); enqueue_hugetlb_folio(h, folio); + spin_unlock_irqrestore(&hugetlb_lock, flags); } - spin_unlock_irqrestore(&hugetlb_lock, flags); } /* * Put bootmem huge pages into the standard lists after mem_map is up. * Note: This only applies to gigantic (order > MAX_PAGE_ORDER) pages. */ -static void __init gather_bootmem_prealloc(void) +static void __init gather_bootmem_prealloc_node(unsigned long nid) { LIST_HEAD(folio_list); struct huge_bootmem_page *m; struct hstate *h = NULL, *prev_h = NULL; - list_for_each_entry(m, &huge_boot_pages, list) { + list_for_each_entry(m, &huge_boot_pages[nid], list) { struct page *page = virt_to_page(m); struct folio *folio = (void *)page; @@ -3453,6 +3453,31 @@ static void __init gather_bootmem_preall prep_and_add_bootmem_folios(h, &folio_list); } +static void __init gather_bootmem_prealloc_parallel(unsigned long start, + unsigned long end, void *arg) +{ + int nid; + + for (nid = start; nid < end; nid++) + gather_bootmem_prealloc_node(nid); +} + +static void __init gather_bootmem_prealloc(void) +{ + struct padata_mt_job job = { + .thread_fn = gather_bootmem_prealloc_parallel, + .fn_arg = NULL, + .start = 0, + .size = num_node_state(N_MEMORY), + .align = 1, + .min_chunk = 1, + .max_threads = num_node_state(N_MEMORY), + .numa_aware = true, + }; + + padata_do_multithreaded(&job); +} + static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid) { unsigned long i; @@ -3600,6 +3625,7 @@ static unsigned long __init hugetlb_page static void __init hugetlb_hstate_alloc_pages(struct hstate *h) { unsigned long allocated; + static bool initialied __initdata; /* skip gigantic hugepages allocation if hugetlb_cma enabled */ if (hstate_is_gigantic(h) && hugetlb_cma_size) { @@ -3607,6 +3633,15 @@ static void __init hugetlb_hstate_alloc_ return; } + /* hugetlb_hstate_alloc_pages will be called many times, initialize huge_boot_pages once */ + if (!initialied) { + int i = 0; + + for (i = 0; i < MAX_NUMNODES; i++) + INIT_LIST_HEAD(&huge_boot_pages[i]); + initialied = true; + } + /* do node specific alloc */ if (hugetlb_hstate_alloc_pages_specific_nodes(h)) return; _ Patches currently in -mm which might be from gang.li@xxxxxxxxx are hugetlb-code-clean-for-hugetlb_hstate_alloc_pages.patch hugetlb-split-hugetlb_hstate_alloc_pages.patch hugetlb-pass-next_nid_to_alloc-directly-to-for_each_node_mask_to_alloc.patch padata-dispatch-works-on-different-nodes.patch padata-downgrade-padata_do_multithreaded-to-serial-execution-for-non-smp.patch hugetlb-have-config_hugetlbfs-select-config_padata.patch hugetlb-parallelize-2m-hugetlb-allocation-and-initialization.patch hugetlb-parallelize-1g-hugetlb-initialization.patch