| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <ef5b09e9-8cfb-4e74-89d4-5ebde12361cf@linux.dev>
Date: Wed, 24 Jan 2024 18:52:19 +0800
From: Gang Li <gang.li@...ux.dev>
To: Muchun Song <muchun.song@...ux.dev>
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org,
ligang.bdlg@...edance.com, David Hildenbrand <david@...hat.com>,
David Rientjes <rientjes@...gle.com>, Mike Kravetz
<mike.kravetz@...cle.com>, Andrew Morton <akpm@...ux-foundation.org>,
Tim Chen <tim.c.chen@...ux.intel.com>
Subject: Re: [PATCH v4 7/7] hugetlb: parallelize 1G hugetlb initialization
On 2024/1/24 17:23, Muchun Song wrote:
> On 2024/1/18 20:39, 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 no patch(ms) patched(ms) saved
>> ------------------- -------------- ------------- --------
>> 256c2t(4 node) 1G 4745 2024 57.34%
>
> What does "256c2t" mean?
A machine with 256 core and 2T memory.
>
>> 128c1t(2 node) 1G 3358 1712 49.02%
>> 12t 1G 77000 18300 76.23%
>>
>> Signed-off-by: Gang Li <gang.li@...ux.dev>
>> Tested-by: David Rientjes <rientjes@...gle.com>
>> ---
>> include/linux/hugetlb.h | 2 +-
>> mm/hugetlb.c | 42 +++++++++++++++++++++++++++++++++--------
>> 2 files changed, 35 insertions(+), 9 deletions(-)
>>
>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>> index c1ee640d87b1..77b30a8c6076 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 9b348ba418f5..2f4b77630ada 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;
>
> Why not use nid directly in the following list_add()?
`node` may be changed in `for_each_node_mask_to_alloc`.
>
>> /* 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(unsigned long start,
>> unsigned long end, void *arg)
>
> This function name could be gather_bootmem_prealloc_node.
>
LGTM.
>> +
>> {
>> + int nid = start;
>> 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,
>> + .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;
>> @@ -3602,6 +3620,14 @@ static void __init
>> hugetlb_hstate_alloc_pages(struct hstate *h)
>> return;
>> }
>> + /* hugetlb_hstate_alloc_pages will be called many times, init
>> huge_boot_pages once*/
>
> s/init/initialize/g
>
> And you miss a black right before "*/".
OK
>
>> + if (huge_boot_pages[0].next == NULL) {
>
> It it not intuitive. I'd like to use a 'initialied' variable
Would it make the code look a bit redundant?
> to indicate whether it has been initialized. BTW, it can be
> marked as __initdata.
>
OK
Powered by blists - more mailing lists