On Wed 19-08-20 12:11:50, David Hildenbrand wrote:
> We make sure that we cannot have any memory holes right at the beginning
> of offline_pages(). We no longer need walk_system_ram_range() and can
> call __offline_isolated_pages() directly.
>
> offlined_pages always corresponds to nr_pages, so we can simplify that.
I would probably fold this into the previous patch as they are dealing
with the same thing.
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
> Cc: Baoquan He <bhe@xxxxxxxxxx>
> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
> Cc: Oscar Salvador <osalvador@xxxxxxx>
> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> mm/memory_hotplug.c | 28 ++++++++--------------------
> 1 file changed, 8 insertions(+), 20 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index f64478349148d..50aa5df696e9d 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1373,17 +1373,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
> return ret;
> }
>
> -/* Mark all sections offline and remove all free pages from the buddy. */
> -static int
> -offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages,
> - void *data)
> -{
> - unsigned long *offlined_pages = (unsigned long *)data;
> -
> - *offlined_pages += __offline_isolated_pages(start, start + nr_pages);
> - return 0;
> -}
> -
> static int __init cmdline_parse_movable_node(char *p)
> {
> movable_node_enabled = true;
> @@ -1470,7 +1459,7 @@ static int count_system_ram_pages_cb(unsigned long start_pfn,
> int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> {
> const unsigned long end_pfn = start_pfn + nr_pages;
> - unsigned long pfn, system_ram_pages = 0, offlined_pages = 0;
> + unsigned long pfn, system_ram_pages = 0;
> int ret, node, nr_isolate_pageblock;
> unsigned long flags;
> struct zone *zone;
> @@ -1570,11 +1559,10 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> }
> } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE));
>
> - /* Ok, all of our target is isolated.
> - We cannot do rollback at this point. */
> - walk_system_ram_range(start_pfn, end_pfn - start_pfn,
> - &offlined_pages, offline_isolated_pages_cb);
> - pr_info("Offlined Pages %ld\n", offlined_pages);
> + /* Mark all sections offline and remove free pages from the buddy. */
> + __offline_isolated_pages(start_pfn, end_pfn);
> + pr_info("Offlined Pages %ld\n", nr_pages);
> +
> /*
> * Onlining will reset pagetype flags and makes migrate type
> * MOVABLE, so just need to decrease the number of isolated
> @@ -1585,11 +1573,11 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> spin_unlock_irqrestore(&zone->lock, flags);
>
> /* removal success */
> - adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages);
> - zone->present_pages -= offlined_pages;
> + adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages);
> + zone->present_pages -= nr_pages;
>
> pgdat_resize_lock(zone->zone_pgdat, &flags);
> - zone->zone_pgdat->node_present_pages -= offlined_pages;
> + zone->zone_pgdat->node_present_pages -= nr_pages;
> pgdat_resize_unlock(zone->zone_pgdat, &flags);
>
> init_per_zone_wmark_min();
> --
> 2.26.2
>
--
Michal Hocko
SUSE Labs
