On 2024/1/26 23:24, Gang Li wrote:
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%
Signed-off-by: Gang Li <ligang.bdlg@xxxxxxxxxxxxx>
Tested-by: David Rientjes <rientjes@xxxxxxxxxx>
---
arch/powerpc/mm/hugetlbpage.c | 2 +-
include/linux/hugetlb.h | 2 +-
mm/hugetlb.c | 44 ++++++++++++++++++++++++++++-------
3 files changed, 38 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 0a540b37aab62..a1651d5471862 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -226,7 +226,7 @@ static int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate)
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;
}
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index c1ee640d87b11..77b30a8c6076b 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -178,7 +178,7 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,
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 */
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 385840397bce5..eee0c456f6571 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -69,7 +69,7 @@ static bool hugetlb_cma_folio(struct folio *folio, unsigned int order)
#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 hstate *h, int nid)
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 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid)
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_folios(struct hstate *h,
/* 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 +3402,27 @@ static void __init prep_and_add_bootmem_folios(struct hstate *h,
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 start, unsigned long end, void *arg)
+
{
+ int nid = start;
Sorry for so late to notice an issue here. I have seen a comment from
PADATA, whcih says:
@max_threads: Max threads to use for the job, actual number may be less
depending on task size and minimum chunk size.
PADATA will not guarantee gather_bootmem_prealloc_node() will be called
->max_threads times (You have initialized it to the number of NUMA nodes in
gather_bootmem_prealloc). Therefore, we should add a loop here to initialize
multiple nodes, namely (@end - @start) here. Otherwise, we will miss
initializing some nodes.
Thanks.
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 +3455,22 @@ static void __init gather_bootmem_prealloc(void)
prep_and_add_bootmem_folios(h, &folio_list);
}
+static void __init gather_bootmem_prealloc(void)
+{
+ struct padata_mt_job job = {
+ .thread_fn = gather_bootmem_prealloc_node,
+ .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 +3618,7 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h)
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 +3626,15 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
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;
