On 06/08/2017 09:45 AM, Michal Hocko wrote:
> From: Michal Hocko <mhocko@xxxxxxxx>
>
> 394e31d2ceb4 ("mem-hotplug: alloc new page from a nearest neighbor node
> when mem-offline") has duplicated a large part of alloc_migrate_target
> with some hotplug specific special casing. To be more precise it tried
> to enfore the allocation from a different node than the original page.
> As a result the two function diverged in their shared logic, e.g. the
> hugetlb allocation strategy. Let's unify the two and express different
> NUMA requirements by the given nodemask. new_node_page will simply
> exclude the node it doesn't care about and alloc_migrate_target will
> use all the available nodes. alloc_migrate_target will then learn to
> migrate hugetlb pages more sanely and use preallocated pool when
> possible.
>
> Please note that alloc_migrate_target used to call alloc_page resp.
> alloc_pages_current so the memory policy of the current context which
> is quite strange when we consider that it is used in the context of
> alloc_contig_range which just tries to migrate pages which stand in the
> way.
>
> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index 3606104893e0..757410d9f758 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -8,6 +8,7 @@
> #include <linux/memory.h>
> #include <linux/hugetlb.h>
> #include <linux/page_owner.h>
> +#include <linux/migrate.h>
> #include "internal.h"
>
> #define CREATE_TRACE_POINTS
> @@ -294,20 +295,5 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
> struct page *alloc_migrate_target(struct page *page, unsigned long private,
> int **resultp)
> {
> - gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
> -
> - /*
> - * TODO: allocate a destination hugepage from a nearest neighbor node,
> - * accordance with memory policy of the user process if possible. For
> - * now as a simple work-around, we use the next node for destination.
> - */
> - if (PageHuge(page))
> - return alloc_huge_page_node(page_hstate(compound_head(page)),
> - next_node_in(page_to_nid(page),
> - node_online_map));
> -
> - if (PageHighMem(page))
> - gfp_mask |= __GFP_HIGHMEM;
> -
> - return alloc_page(gfp_mask);
> + return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
This replaces the N_ONLINE (node_online_map) with N_MEMORY for huge
pages. Assuming that's OK.
> }
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
