On Fri, Sep 28, 2018 at 12:19:44AM +0000, Naoya Horiguchi wrote:
> On Tue, Sep 25, 2018 at 11:35:32AM -0400, Masayoshi Mizuma wrote:
> > From: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
> >
> > 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 <pavel.tatashin@xxxxxxxxxxxxx>
> > Reviewed-off-by: Masayoshi Mizuma <m.mizuma@xxxxxxxxxxxxxx>
>
> According to convention, review tag is formatted like "Reviewed-by: ...",
Sorry for the typo...
> Otherwise, looks good to me.
>
> Acked-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Thanks!
- Masa
>
> > ---
> > 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
> >
> >
