Re: [PATCH v4] mm: pass nid to reserve_bootmem_region()

From: Mike Rapoport
Date: Tue Jun 20 2023 - 04:46:15 EST


On Mon, Jun 19, 2023 at 10:34:06AM +0800, Yajun Deng wrote:
> early_pfn_to_nid() is called frequently in init_reserved_page(), it
> returns the node id of the PFN. These PFN are probably from the same
> memory region, they have the same node id. It's not necessary to call
> early_pfn_to_nid() for each PFN.
>
> Pass nid to reserve_bootmem_region() and drop the call to
> early_pfn_to_nid() in init_reserved_page(). Also, set nid on all
> reserved pages before doing this, as some reserved memory regions may
> not be set nid.
>
> The most beneficial function is memmap_init_reserved_pages() if
> CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled.
>
> The following data was tested on an x86 machine with 190GB of RAM.
>
> before:
> memmap_init_reserved_pages() 67ms
>
> after:
> memmap_init_reserved_pages() 20ms
>
> Signed-off-by: Yajun Deng <yajun.deng@xxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202306160145.juJMr3Bi-lkp@xxxxxxxxx

Reviewed-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> ---
> V3 -> V4: make the test for early_page_initialised() inside if
> (IS_ENABLED(CONFIG_DEFERRED_STRUCT_PAGE_INIT))
> V2 -> V3: set nid on all reserved pages before pass nid.
> V1 -> V2: fix build error when CONFIG_NUMA is not enabled.
> ---
> include/linux/mm.h | 3 ++-
> mm/memblock.c | 31 +++++++++++++++++++++----------
> mm/mm_init.c | 30 +++++++++++++++++-------------
> 3 files changed, 40 insertions(+), 24 deletions(-)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index fdd966b11f79..a7a0e692d44d 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2960,7 +2960,8 @@ extern unsigned long free_reserved_area(void *start, void *end,
>
> extern void adjust_managed_page_count(struct page *page, long count);
>
> -extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
> +extern void reserve_bootmem_region(phys_addr_t start,
> + phys_addr_t end, int nid);
>
> /* Free the reserved page into the buddy system, so it gets managed. */
> static inline void free_reserved_page(struct page *page)
> diff --git a/mm/memblock.c b/mm/memblock.c
> index ff0da1858778..f9e61e565a53 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -2091,19 +2091,30 @@ static void __init memmap_init_reserved_pages(void)
> {
> struct memblock_region *region;
> phys_addr_t start, end;
> - u64 i;
> + int nid;
> +
> + /*
> + * set nid on all reserved pages and also treat struct
> + * pages for the NOMAP regions as PageReserved
> + */
> + for_each_mem_region(region) {
> + nid = memblock_get_region_node(region);
> + start = region->base;
> + end = start + region->size;
> +
> + if (memblock_is_nomap(region))
> + reserve_bootmem_region(start, end, nid);
> +
> + memblock_set_node(start, end, &memblock.reserved, nid);
> + }
>
> /* initialize struct pages for the reserved regions */
> - for_each_reserved_mem_range(i, &start, &end)
> - reserve_bootmem_region(start, end);
> + for_each_reserved_mem_region(region) {
> + nid = memblock_get_region_node(region);
> + start = region->base;
> + end = start + region->size;
>
> - /* and also treat struct pages for the NOMAP regions as PageReserved */
> - for_each_mem_region(region) {
> - if (memblock_is_nomap(region)) {
> - start = region->base;
> - end = start + region->size;
> - reserve_bootmem_region(start, end);
> - }
> + reserve_bootmem_region(start, end, nid);
> }
> }
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index d393631599a7..a1963c3322af 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -646,10 +646,8 @@ static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
> }
>
> /* Returns true if the struct page for the pfn is initialised */
> -static inline bool __meminit early_page_initialised(unsigned long pfn)
> +static inline bool __meminit early_page_initialised(unsigned long pfn, int nid)
> {
> - int nid = early_pfn_to_nid(pfn);
> -
> if (node_online(nid) && pfn >= NODE_DATA(nid)->first_deferred_pfn)
> return false;
>
> @@ -695,15 +693,14 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
> return false;
> }
>
> -static void __meminit init_reserved_page(unsigned long pfn)
> +static void __meminit init_reserved_page(unsigned long pfn, int nid)
> {
> pg_data_t *pgdat;
> - int nid, zid;
> + int zid;
>
> - if (early_page_initialised(pfn))
> + if (early_page_initialised(pfn, nid))
> return;
>
> - nid = early_pfn_to_nid(pfn);
> pgdat = NODE_DATA(nid);
>
> for (zid = 0; zid < MAX_NR_ZONES; zid++) {
> @@ -717,7 +714,7 @@ static void __meminit init_reserved_page(unsigned long pfn)
> #else
> static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
>
> -static inline bool early_page_initialised(unsigned long pfn)
> +static inline bool early_page_initialised(unsigned long pfn, int nid)
> {
> return true;
> }
> @@ -727,7 +724,7 @@ static inline bool defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
> return false;
> }
>
> -static inline void init_reserved_page(unsigned long pfn)
> +static inline void init_reserved_page(unsigned long pfn, int nid)
> {
> }
> #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
> @@ -738,7 +735,8 @@ static inline void init_reserved_page(unsigned long pfn)
> * marks the pages PageReserved. The remaining valid pages are later
> * sent to the buddy page allocator.
> */
> -void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
> +void __meminit reserve_bootmem_region(phys_addr_t start,
> + phys_addr_t end, int nid)
> {
> unsigned long start_pfn = PFN_DOWN(start);
> unsigned long end_pfn = PFN_UP(end);
> @@ -747,7 +745,7 @@ void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
> if (pfn_valid(start_pfn)) {
> struct page *page = pfn_to_page(start_pfn);
>
> - init_reserved_page(start_pfn);
> + init_reserved_page(start_pfn, nid);
>
> /* Avoid false-positive PageTail() */
> INIT_LIST_HEAD(&page->lru);
> @@ -2579,8 +2577,14 @@ void __init set_dma_reserve(unsigned long new_dma_reserve)
> void __init memblock_free_pages(struct page *page, unsigned long pfn,
> unsigned int order)
> {
> - if (!early_page_initialised(pfn))
> - return;
> +
> + if (IS_ENABLED(CONFIG_DEFERRED_STRUCT_PAGE_INIT)) {
> + int nid = early_pfn_to_nid(pfn);
> +
> + if (!early_page_initialised(pfn, nid))
> + return;
> + }
> +
> if (!kmsan_memblock_free_pages(page, order)) {
> /* KMSAN will take care of these pages. */
> return;
> --
> 2.25.1
>

--
Sincerely yours,
Mike.