| Message ID | 20240703005151.28712-1-richard.weiyang@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/3] mm/memblock: introduce a new helper memblock_estimated_nr_pages() | expand |
On Wed, Jul 03, 2024 at 12:51:49AM +0000, Wei Yang wrote: > Instead of using raw memblock api, we wrap a new helper for user. The changelog should be more elaborate and explain why this function is needed. > Signed-off-by: Wei Yang <richard.weiyang@gmail.com> > --- > include/linux/memblock.h | 1 + > mm/memblock.c | 19 +++++++++++++++++++ > 2 files changed, 20 insertions(+) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 40c62aca36ec..7d1c32b3dc12 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -486,6 +486,7 @@ static inline __init_memblock bool memblock_bottom_up(void) > > phys_addr_t memblock_phys_mem_size(void); > phys_addr_t memblock_reserved_size(void); > +unsigned long memblock_estimated_nr_pages(void); > phys_addr_t memblock_start_of_DRAM(void); > phys_addr_t memblock_end_of_DRAM(void); > void memblock_enforce_memory_limit(phys_addr_t memory_limit); > diff --git a/mm/memblock.c b/mm/memblock.c > index e81fb68f7f88..c1f1aac0459f 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1729,6 +1729,25 @@ phys_addr_t __init_memblock memblock_reserved_size(void) > return memblock.reserved.total_size; > } > > +/** > + * memblock_estimated_nr_pages - return number of pages from memblock point of > + * view This function returns the estimate for free pages, not the number of pages in RAM. How about memblock_estimated_nr_free_pages()? > + * some calculation before all pages are freed to buddy system, especially > + * when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled. I'm failing to parse this sentence. The return value here won't depend on CONFIG_DEFERRED_STRUCT_PAGE_INIT. > + * > + * At this point, we can get this information from memblock. Since the system > + * state is not settle down and address alignment, the value is an estimation. > + * > + * Return: > + * An estimated number of pages from memblock point of view. ^ free > + */ > +unsigned long __init memblock_estimated_nr_pages(void) > +{ > + return PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_size()); > +} > + > /* lowest address */ > phys_addr_t __init_memblock memblock_start_of_DRAM(void) > { > -- > 2.34.1 >
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 40c62aca36ec..7d1c32b3dc12 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -486,6 +486,7 @@ static inline __init_memblock bool memblock_bottom_up(void) phys_addr_t memblock_phys_mem_size(void); phys_addr_t memblock_reserved_size(void); +unsigned long memblock_estimated_nr_pages(void); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); diff --git a/mm/memblock.c b/mm/memblock.c index e81fb68f7f88..c1f1aac0459f 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1729,6 +1729,25 @@ phys_addr_t __init_memblock memblock_reserved_size(void) return memblock.reserved.total_size; } +/** + * memblock_estimated_nr_pages - return number of pages from memblock point of + * view + * + * During bootup, system may need number of pages in the whole system to do + * some calculation before all pages are freed to buddy system, especially + * when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled. + * + * At this point, we can get this information from memblock. Since the system + * state is not settle down and address alignment, the value is an estimation. + * + * Return: + * An estimated number of pages from memblock point of view. + */ +unsigned long __init memblock_estimated_nr_pages(void) +{ + return PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_size()); +} + /* lowest address */ phys_addr_t __init_memblock memblock_start_of_DRAM(void) {
Instead of using raw memblock api, we wrap a new helper for user. Signed-off-by: Wei Yang <richard.weiyang@gmail.com> --- include/linux/memblock.h | 1 + mm/memblock.c | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+)