Expand the usage of the struct alloc_context introduced in the previous patch
also for calling try_to_compact_pages(), to reduce the number of its
parameters. Since the function is in different compilation unit, we need to
move alloc_context definition in the shared mm/internal.h header.
With this change we get simpler code and small savings of code size and stack
usage:
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-27 (-27)
function old new delta
__alloc_pages_direct_compact 283 256 -27
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-13 (-13)
function old new delta
try_to_compact_pages 582 569 -13
Stack usage of __alloc_pages_direct_compact goes from 24 to none (per
scripts/checkstack.pl).
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
include/linux/compaction.h | 17 +++++++++--------
mm/compaction.c | 23 +++++++++++------------
mm/internal.h | 22 ++++++++++++++++++++++
mm/page_alloc.c | 27 ++-------------------------
4 files changed, 44 insertions(+), 45 deletions(-)
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 3238ffa..f2efda2 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -21,6 +21,8 @@
/* Zone lock or lru_lock was contended in async compaction */
#define COMPACT_CONTENDED_LOCK 2
+struct alloc_context; /* in mm/internal.h */
+
#ifdef CONFIG_COMPACTION
extern int sysctl_compact_memory;
extern int sysctl_compaction_handler(struct ctl_table *table, int write,
@@ -30,10 +32,9 @@ extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, loff_t *ppos);
extern int fragmentation_index(struct zone *zone, unsigned int order);
-extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
- int order, gfp_t gfp_mask, nodemask_t *mask,
- enum migrate_mode mode, int *contended,
- int alloc_flags, int classzone_idx);
+extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
+ int alloc_flags, const struct alloc_context *ac,
+ enum migrate_mode mode, int *contended);
extern void compact_pgdat(pg_data_t *pgdat, int order);
extern void reset_isolation_suitable(pg_data_t *pgdat);
extern unsigned long compaction_suitable(struct zone *zone, int order,
@@ -101,10 +102,10 @@ static inline bool compaction_restarting(struct zone *zone, int order)
}
#else
-static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
- int order, gfp_t gfp_mask, nodemask_t *nodemask,
- enum migrate_mode mode, int *contended,
- int alloc_flags, int classzone_idx)
+static inline unsigned long try_to_compact_pages(gfp_t gfp_mask,
+ unsigned int order, int alloc_flags,
+ const struct alloc_context *ac,
+ enum migrate_mode mode, int *contended)
{
return COMPACT_CONTINUE;
}
diff --git a/mm/compaction.c b/mm/compaction.c
index 546e571..9c7e690 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1335,22 +1335,20 @@ int sysctl_extfrag_threshold = 500;
/**
* try_to_compact_pages - Direct compact to satisfy a high-order allocation
- * @zonelist: The zonelist used for the current allocation
- * @order: The order of the current allocation
* @gfp_mask: The GFP mask of the current allocation
- * @nodemask: The allowed nodes to allocate from
+ * @order: The order of the current allocation
+ * @alloc_flags: The allocation flags of the current allocation
+ * @ac: The context of current allocation
* @mode: The migration mode for async, sync light, or sync migration
* @contended: Return value that determines if compaction was aborted due to
* need_resched() or lock contention
*
* This is the main entry point for direct page compaction.
*/
-unsigned long try_to_compact_pages(struct zonelist *zonelist,
- int order, gfp_t gfp_mask, nodemask_t *nodemask,
- enum migrate_mode mode, int *contended,
- int alloc_flags, int classzone_idx)
+unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
+ int alloc_flags, const struct alloc_context *ac,
+ enum migrate_mode mode, int *contended)
{
- enum zone_type high_zoneidx = gfp_zone(gfp_mask);
int may_enter_fs = gfp_mask & __GFP_FS;
int may_perform_io = gfp_mask & __GFP_IO;
struct zoneref *z;
@@ -1365,8 +1363,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
return COMPACT_SKIPPED;
/* Compact each zone in the list */
- for_each_zone_zonelist_nodemask(zone, z, zonelist, high_zoneidx,
- nodemask) {
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
+ ac->nodemask) {
int status;
int zone_contended;
@@ -1374,7 +1372,8 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
continue;
status = compact_zone_order(zone, order, gfp_mask, mode,
- &zone_contended, alloc_flags, classzone_idx);
+ &zone_contended, alloc_flags,
+ ac->classzone_idx);
rc = max(status, rc);
/*
* It takes at least one zone that wasn't lock contended
@@ -1384,7 +1383,7 @@ unsigned long try_to_compact_pages(struct zonelist *zonelist,
/* If a normal allocation would succeed, stop compacting */
if (zone_watermark_ok(zone, order, low_wmark_pages(zone),
- classzone_idx, alloc_flags)) {
+ ac->classzone_idx, alloc_flags)) {
/*
* We think the allocation will succeed in this zone,
* but it is not certain, hence the false. The caller
diff --git a/mm/internal.h b/mm/internal.h
index efad241..c4d6c9b 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -110,6 +110,28 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
*/
/*
+ * Structure for holding the mostly immutable allocation parameters passed
+ * between functions involved in allocations, including the alloc_pages*
+ * family of functions.
+ *
+ * nodemask, migratetype and high_zoneidx are initialized only once in
+ * __alloc_pages_nodemask() and then never change.
+ *
+ * zonelist, preferred_zone and classzone_idx are set first in
+ * __alloc_pages_nodemask() for the fast path, and might be later changed
+ * in __alloc_pages_slowpath(). All other functions pass the whole strucure
+ * by a const pointer.
+ */
+struct alloc_context {
+ struct zonelist *zonelist;
+ nodemask_t *nodemask;
+ struct zone *preferred_zone;
+ int classzone_idx;
+ int migratetype;
+ enum zone_type high_zoneidx;
+};
+
+/*
* Locate the struct page for both the matching buddy in our
* pair (buddy1) and the combined O(n+1) page they form (page).
*
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bdbae0a..12d55b8 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -232,27 +232,6 @@ EXPORT_SYMBOL(nr_node_ids);
EXPORT_SYMBOL(nr_online_nodes);
#endif
-/*
- * Structure for holding the mostly immutable allocation parameters passed
- * between alloc_pages* family of functions.
- *
- * nodemask, migratetype and high_zoneidx are initialized only once in
- * __alloc_pages_nodemask() and then never change.
- *
- * zonelist, preferred_zone and classzone_idx are set first in
- * __alloc_pages_nodemask() for the fast path, and might be later changed
- * in __alloc_pages_slowpath(). All other functions pass the whole strucure
- * by a const pointer.
- */
-struct alloc_context {
- struct zonelist *zonelist;
- nodemask_t *nodemask;
- struct zone *preferred_zone;
- int classzone_idx;
- int migratetype;
- enum zone_type high_zoneidx;
-};
-
int page_group_by_mobility_disabled __read_mostly;
void set_pageblock_migratetype(struct page *page, int migratetype)
@@ -2396,10 +2375,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
return NULL;
current->flags |= PF_MEMALLOC;
- compact_result = try_to_compact_pages(ac->zonelist, order, gfp_mask,
- ac->nodemask, mode,
- contended_compaction,
- alloc_flags, ac->classzone_idx);
+ compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
+ mode, contended_compaction);
current->flags &= ~PF_MEMALLOC;
switch (compact_result) {
--
2.1.2
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