On Thu, Sep 22, 2016 at 05:59:46PM +0200, Vlastimil Babka wrote:
> On 09/22/2016 08:50 AM, Joonsoo Kim wrote:
> >On Thu, Sep 22, 2016 at 02:45:46PM +0900, Joonsoo Kim wrote:
> >>>
> >>> > /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
> >>> > void __init init_cma_reserved_pageblock(struct page *page)
> >>> > {
> >>> > unsigned i = pageblock_nr_pages;
> >>> >+ unsigned long pfn = page_to_pfn(page);
> >>> > struct page *p = page;
> >>> >+ int nid = page_to_nid(page);
> >>> >+
> >>> >+ /*
> >>> >+ * ZONE_CMA will steal present pages from other zones by
> >>> >changing
> >>> >+ * page links so page_zone() is changed. Before that,
> >>> >+ * we need to adjust previous zone's page count first.
> >>> >+ */
> >>> >+ adjust_present_page_count(page, -pageblock_nr_pages);
> >>> >
> >>> > do {
> >>> > __ClearPageReserved(p);
> >>> > set_page_count(p, 0);
> >>> >- } while (++p, --i);
> >>> >+
> >>> >+ /* Steal pages from other zones */
> >>> >+ set_page_links(p, ZONE_CMA, nid, pfn);
> >>> >+ } while (++p, ++pfn, --i);
> >>> >+
> >>> >+ adjust_present_page_count(page, pageblock_nr_pages);
> >>>
> >>> This seems to assign pages to ZONE_CMA on the proper node, which is
> >>> good. But then ZONE_CMA on multiple nodes will have unnecessary
> >>> holes in the spanned pages, as each will contain only a subset.
> >>
> >>True, I will fix it and respin the series.
> >
> >I now realize that it's too late to send full series for next
> >merge window. I will send full series after next merge window is closed.
>
> I think there might still be rc8 thus another week.
Indeed. I will send full series, soon.
>
> >Anyway, I'd like to confirm that following incremental patch will solve
> >your concern.
>
> Yeah that should work, as long as single cma areas don't include multiple
> nodes?
Single cma areas cannot include multiple nodes at least until now.
There is a check that single cma area is on a single zone.
Thanks.
>
> >Thanks.
> >
> >
> >------>8--------------
> > mm/cma.c | 25 ++++++++++++++++---------
> > 1 file changed, 16 insertions(+), 9 deletions(-)
> >
> >diff --git a/mm/cma.c b/mm/cma.c
> >index d69bdf7..8375554 100644
> >--- a/mm/cma.c
> >+++ b/mm/cma.c
> >@@ -146,22 +146,29 @@ static int __init cma_init_reserved_areas(void)
> > {
> > int i;
> > struct zone *zone;
> >- unsigned long start_pfn = UINT_MAX, end_pfn = 0;
> >+ pg_data_t *pgdat;
> >
> > if (!cma_area_count)
> > return 0;
> >
> >- for (i = 0; i < cma_area_count; i++) {
> >- if (start_pfn > cma_areas[i].base_pfn)
> >- start_pfn = cma_areas[i].base_pfn;
> >- if (end_pfn < cma_areas[i].base_pfn + cma_areas[i].count)
> >- end_pfn = cma_areas[i].base_pfn + cma_areas[i].count;
> >- }
> >+ for_each_online_pgdat(pgdat) {
> >+ unsigned long start_pfn = UINT_MAX, end_pfn = 0;
> >
> >- for_each_zone(zone) {
> >- if (!is_zone_cma(zone))
> >+ for (i = 0; i < cma_area_count; i++) {
> >+ if (page_to_nid(pfn_to_page(cma_areas[i].base_pfn))
> >!=
>
> We have pfn_to_nid() (although the implementation is just like this).
Will fix.
Thanks.
