On Tue, Sep 25, 2018 at 11:35:32AM -0400, Masayoshi Mizuma wrote: > From: Pavel Tatashin <[email protected]> > > When checking for valid pfns in zero_resv_unavail(), it is not necessary to > verify that pfns within pageblock_nr_pages ranges are valid, only the first > one needs to be checked. This is because memory for pages are allocated in > contiguous chunks that contain pageblock_nr_pages struct pages. > > Signed-off-by: Pavel Tatashin <[email protected]> > Reviewed-off-by: Masayoshi Mizuma <[email protected]>
According to convention, review tag is formatted like "Reviewed-by: ...", Otherwise, looks good to me. Acked-by: Naoya Horiguchi <[email protected]> > --- > mm/page_alloc.c | 46 ++++++++++++++++++++++++++-------------------- > 1 file changed, 26 insertions(+), 20 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3b9d89e..bd5b7e4 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -6440,6 +6440,29 @@ void __init free_area_init_node(int nid, unsigned long > *zones_size, > } > > #if defined(CONFIG_HAVE_MEMBLOCK) && !defined(CONFIG_FLAT_NODE_MEM_MAP) > + > +/* > + * Zero all valid struct pages in range [spfn, epfn), return number of struct > + * pages zeroed > + */ > +static u64 zero_pfn_range(unsigned long spfn, unsigned long epfn) > +{ > + unsigned long pfn; > + u64 pgcnt = 0; > + > + for (pfn = spfn; pfn < epfn; pfn++) { > + if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) { > + pfn = ALIGN_DOWN(pfn, pageblock_nr_pages) > + + pageblock_nr_pages - 1; > + continue; > + } > + mm_zero_struct_page(pfn_to_page(pfn)); > + pgcnt++; > + } > + > + return pgcnt; > +} > + > /* > * Only struct pages that are backed by physical memory are zeroed and > * initialized by going through __init_single_page(). But, there are some > @@ -6455,7 +6478,6 @@ void __init free_area_init_node(int nid, unsigned long > *zones_size, > void __init zero_resv_unavail(void) > { > phys_addr_t start, end; > - unsigned long pfn; > u64 i, pgcnt; > phys_addr_t next = 0; > > @@ -6465,34 +6487,18 @@ void __init zero_resv_unavail(void) > pgcnt = 0; > for_each_mem_range(i, &memblock.memory, NULL, > NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) { > - if (next < start) { > - for (pfn = PFN_DOWN(next); pfn < PFN_UP(start); pfn++) { > - if (!pfn_valid(ALIGN_DOWN(pfn, > pageblock_nr_pages))) > - continue; > - mm_zero_struct_page(pfn_to_page(pfn)); > - pgcnt++; > - } > - } > + if (next < start) > + pgcnt += zero_pfn_range(PFN_DOWN(next), PFN_UP(start)); > next = end; > } > - for (pfn = PFN_DOWN(next); pfn < max_pfn; pfn++) { > - if (!pfn_valid(ALIGN_DOWN(pfn, pageblock_nr_pages))) > - continue; > - mm_zero_struct_page(pfn_to_page(pfn)); > - pgcnt++; > - } > - > + pgcnt += zero_pfn_range(PFN_DOWN(next), max_pfn); > > /* > * Struct pages that do not have backing memory. This could be because > * firmware is using some of this memory, or for some other reasons. > - * Once memblock is changed so such behaviour is not allowed: i.e. > - * list of "reserved" memory must be a subset of list of "memory", then > - * this code can be removed. > */ > if (pgcnt) > pr_info("Zeroed struct page in unavailable ranges: %lld pages", > pgcnt); > - > } > #endif /* CONFIG_HAVE_MEMBLOCK && !CONFIG_FLAT_NODE_MEM_MAP */ > > -- > 2.18.0 > >
