[v4,7/7] hugetlb: parallelize 1G hugetlb initialization

  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%
  128c1t(2 node) 1G           3358          1712   49.02%
      12t        1G          77000         18300   76.23%

Signed-off-by: Gang Li <gang.li@linux.dev>
Tested-by: David Rientjes <rientjes@google.com>
---
 include/linux/hugetlb.h |  2 +-
 mm/hugetlb.c            | 42 +++++++++++++++++++++++++++++++++--------
 2 files changed, 35 insertions(+), 9 deletions(-)
  

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%
>    128c1t(2 node) 1G           3358          1712   49.02%
>        12t        1G          77000         18300   76.23%
> 
> Signed-off-by: Gang Li <gang.li@linux.dev>
> Tested-by: David Rientjes <rientjes@google.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];

Hi, please update arch/powerpc/mm/hugetlbpage.c too, since it
was used in ppc.

>   
>   /* 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;
>   
>   	/* 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)
> +
>   {
> +	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*/
> +	if (huge_boot_pages[0].next == NULL) {
> +		int i = 0;
> +
> +		for (i = 0; i < MAX_NUMNODES; i++)
> +			INIT_LIST_HEAD(&huge_boot_pages[i]);
> +	}
> +
>   	/* do node specific alloc */
>   	if (hugetlb_hstate_alloc_pages_specific_nodes(h))
>   		return;
  

On 2024/1/18 22:22, Kefeng Wang wrote:
> On 2024/1/18 20:39, Gang Li wrote:
>>   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];
> 
> Hi, please update arch/powerpc/mm/hugetlbpage.c too, since it
> was used in ppc.
> 

Thanks, will do
  

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?

>    128c1t(2 node) 1G           3358          1712   49.02%
>        12t        1G          77000         18300   76.23%
>
> Signed-off-by: Gang Li <gang.li@linux.dev>
> Tested-by: David Rientjes <rientjes@google.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()?

>   
>   	/* 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.

> +
>   {
> +	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 "*/".

> +	if (huge_boot_pages[0].next == NULL) {

It it not intuitive. I'd like to use a 'initialied' variable
to indicate whether it has been initialized. BTW, it can be
marked as __initdata.

> +		int i = 0;
> +
> +		for (i = 0; i < MAX_NUMNODES; i++)
> +			INIT_LIST_HEAD(&huge_boot_pages[i]);
> +	}
> +
>   	/* do node specific alloc */
>   	if (hugetlb_hstate_alloc_pages_specific_nodes(h))
>   		return;
  

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@linux.dev>
>> Tested-by: David Rientjes <rientjes@google.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
  

> On Jan 24, 2024, at 18:52, Gang Li <gang.li@linux.dev> wrote:
> 
> 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.

A little confusing. I thought 256c2 is a number in hexadecimal.
The unit of memory should be capital T. We should add a simple
explanation about this.

> 
>>>    128c1t(2 node) 1G           3358          1712   49.02%
>>>        12t        1G          77000         18300   76.23%

I am curious how many NUMA nodes does this system have? I suspect
it should not be one.

>>> 
>>> Signed-off-by: Gang Li <gang.li@linux.dev>
>>> Tested-by: David Rientjes <rientjes@google.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`.

Got it.

> 
>>>       /* 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?

What is redundant?

> 
>> to indicate whether it has been initialized. BTW, it can be
>> marked as __initdata.
>> 
> 
> OK
  

On 2024/1/25 10:48, Muchun Song wrote:>>>>         12t        1G 
  77000         18300   76.23%
> 
> I am curious how many NUMA nodes does this system have? I suspect
> it should not be one.
> 

Hi David Rientjes,

I'm also curious. Can you show us some details about this machine?
Such as `lscpu`.

Thanks!
  

On 2024/1/25 10:48, Muchun Song wrote:
>>>> +    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?
> 
> What is redundant?
> 

I was thinking of adding a global variable at first, but it's possible
to add a local static variable, which is more concise.