Skip to content

Commit

Permalink
mm: unify new_node_page and alloc_migrate_target
Browse files Browse the repository at this point in the history
Commit 394e31d ("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.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Xishi Qiu <[email protected]>
Cc: zhong jiang <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
Michal Hocko authored and torvalds committed Jul 10, 2017
1 parent 4db9b2e commit 8b91323
Show file tree
Hide file tree
Showing 3 changed files with 19 additions and 26 deletions.
16 changes: 16 additions & 0 deletions include/linux/migrate.h
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
#include <linux/mm.h>
#include <linux/mempolicy.h>
#include <linux/migrate_mode.h>
#include <linux/hugetlb.h>

typedef struct page *new_page_t(struct page *page, unsigned long private,
int **reason);
Expand All @@ -30,6 +31,21 @@ enum migrate_reason {
/* In mm/debug.c; also keep sync with include/trace/events/migrate.h */
extern char *migrate_reason_names[MR_TYPES];

static inline struct page *new_page_nodemask(struct page *page,
int preferred_nid, nodemask_t *nodemask)
{
gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;

if (PageHuge(page))
return alloc_huge_page_nodemask(page_hstate(compound_head(page)),
nodemask);

if (PageHighMem(page) || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
gfp_mask |= __GFP_HIGHMEM;

return __alloc_pages_nodemask(gfp_mask, 0, preferred_nid, nodemask);
}

#ifdef CONFIG_MIGRATION

extern void putback_movable_pages(struct list_head *l);
Expand Down
11 changes: 1 addition & 10 deletions mm/memory_hotplug.c
Original file line number Diff line number Diff line change
Expand Up @@ -1433,7 +1433,6 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
static struct page *new_node_page(struct page *page, unsigned long private,
int **result)
{
gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
int nid = page_to_nid(page);
nodemask_t nmask = node_states[N_MEMORY];

Expand All @@ -1446,15 +1445,7 @@ static struct page *new_node_page(struct page *page, unsigned long private,
if (nodes_empty(nmask))
node_set(nid, nmask);

if (PageHuge(page))
return alloc_huge_page_nodemask(
page_hstate(compound_head(page)), &nmask);

if (PageHighMem(page)
|| (zone_idx(page_zone(page)) == ZONE_MOVABLE))
gfp_mask |= __GFP_HIGHMEM;

return __alloc_pages_nodemask(gfp_mask, 0, nid, &nmask);
return new_page_nodemask(page, nid, &nmask);
}

#define NR_OFFLINE_AT_ONCE_PAGES (256)
Expand Down
18 changes: 2 additions & 16 deletions mm/page_isolation.c
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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]);
}

0 comments on commit 8b91323

Please sign in to comment.