[RFC PATCH 2/3] mm, migrate: remove reason argument from new_page_t

Michal Hocko
2017-12-08T16:16:26Z

From: Michal Hocko <mhocko@suse.com>

No allocation callback is using this argument anymore. new_page_node
used to use this parameter to convey node_id resp. migration error
up to move_pages code (do_move_page_to_node_array). The error status
never made it into the final status field and we have a better way
to communicate node id to the status field now. All other allocation
callbacks simply ignored the argument so we can drop it finally.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
include/linux/migrate.h | 3 +--
include/linux/page-isolation.h | 3 +--
mm/compaction.c | 3 +--
mm/internal.h | 2 +-
mm/memory_hotplug.c | 3 +--
mm/mempolicy.c | 6 +++---
mm/migrate.c | 19 ++-----------------
mm/page_isolation.c | 3 +--
8 files changed, 11 insertions(+), 31 deletions(-)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index a2246cf670ba..e5d99ade2319 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -7,8 +7,7 @@
#include <linux/migrate_mode.h>
#include <linux/hugetlb.h>

-typedef struct page *new_page_t(struct page *page, unsigned long private,
- int **reason);
+typedef struct page *new_page_t(struct page *page, unsigned long private);
typedef void free_page_t(struct page *page, unsigned long private);

/*
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index cdad58bbfd8b..4ae347cbc36d 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -63,7 +63,6 @@ undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages);

-struct page *alloc_migrate_target(struct page *page, unsigned long private,
- int **resultp);
+struct page *alloc_migrate_target(struct page *page, unsigned long private);

#endif
diff --git a/mm/compaction.c b/mm/compaction.c
index 10cd757f1006..692d21d63391 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1165,8 +1165,7 @@ static void isolate_freepages(struct compact_control *cc)
* from the isolated freelists in the block we are migrating to.
*/
static struct page *compaction_alloc(struct page *migratepage,
- unsigned long data,
- int **result)
+ unsigned long data)
{
struct compact_control *cc = (struct compact_control *)data;
struct page *freepage;
diff --git a/mm/internal.h b/mm/internal.h
index 1a1bb5d59c15..502d14189794 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -538,5 +538,5 @@ static inline bool is_migrate_highatomic_page(struct page *page)
}

void setup_zone_pageset(struct zone *zone);
-extern struct page *alloc_new_node_page(struct page *page, unsigned long node, int **x);
+extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
#endif /* __MM_INTERNAL_H */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index d0856ab2f28d..d865623edee7 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1347,8 +1347,7 @@ static unsigned long scan_movable_pages(unsigned long start, unsigned long end)
return 0;
}

-static struct page *new_node_page(struct page *page, unsigned long private,
- int **result)
+static struct page *new_node_page(struct page *page, unsigned long private)
{
int nid = page_to_nid(page);
nodemask_t nmask = node_states[N_MEMORY];
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 66c9c79b21be..4d849d3098e5 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -943,7 +943,7 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist,
}

/* page allocation callback for NUMA node migration */
-struct page *alloc_new_node_page(struct page *page, unsigned long node, int **x)
+struct page *alloc_new_node_page(struct page *page, unsigned long node)
{
if (PageHuge(page))
return alloc_huge_page_node(page_hstate(compound_head(page)),
@@ -1108,7 +1108,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
* list of pages handed to migrate_pages()--which is how we get here--
* is in virtual address order.
*/
-static struct page *new_page(struct page *page, unsigned long start, int **x)
+static struct page *new_page(struct page *page, unsigned long start)
{
struct vm_area_struct *vma;
unsigned long uninitialized_var(address);
@@ -1153,7 +1153,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
return -ENOSYS;
}

-static struct page *new_page(struct page *page, unsigned long start, int **x)
+static struct page *new_page(struct page *page, unsigned long start)
{
return NULL;
}
diff --git a/mm/migrate.c b/mm/migrate.c
index 9d7252ea2acd..f9235f0155a4 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1136,10 +1136,9 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
enum migrate_reason reason)
{
int rc = MIGRATEPAGE_SUCCESS;
- int *result = NULL;
struct page *newpage;

- newpage = get_new_page(page, private, &result);
+ newpage = get_new_page(page, private);
if (!newpage)
return -ENOMEM;

@@ -1230,12 +1229,6 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
put_page(newpage);
}

- if (result) {
- if (rc)
- *result = rc;
- else
- *result = page_to_nid(newpage);
- }
return rc;
}

@@ -1263,7 +1256,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
enum migrate_mode mode, int reason)
{
int rc = -EAGAIN;
- int *result = NULL;
int page_was_mapped = 0;
struct page *new_hpage;
struct anon_vma *anon_vma = NULL;
@@ -1280,7 +1272,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
return -ENOSYS;
}

- new_hpage = get_new_page(hpage, private, &result);
+ new_hpage = get_new_page(hpage, private);
if (!new_hpage)
return -ENOMEM;

@@ -1345,12 +1337,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
else
putback_active_hugepage(new_hpage);

- if (result) {
- if (rc)
- *result = rc;
- else
- *result = page_to_nid(new_hpage);
- }
return rc;
}

@@ -1622,7 +1608,6 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes,
}
chunk_node = NUMA_NO_NODE;
}
- err = 0;
out_flush:
/* Make sure we do not overwrite the existing error */
err1 = do_move_pages_to_node(mm, &pagelist, chunk_node);
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 165ed8117bd1..53d801235e22 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -293,8 +293,7 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
return pfn < end_pfn ? -EBUSY : 0;
}

-struct page *alloc_migrate_target(struct page *page, unsigned long private,
- int **resultp)
+struct page *alloc_migrate_target(struct page *page, unsigned long private)
{
return new_page_nodemask(page, numa_node_id(), &node_states[N_MEMORY]);
}
--
2.15.0