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mm: reduce try_to_compact_pages parameters

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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@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vlastimil Babka 2015-02-11 15:25:44 -08:00 committed by Linus Torvalds
parent a9263751e1
commit 1a6d53a105
4 changed files with 44 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include/linux/compaction.h
View File

@ -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;
}

23
mm/compaction.c
View File

@ -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

22
mm/internal.h
View File

@ -109,6 +109,28 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
* in mm/page_alloc.c
*/
/*
* 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).

27
mm/page_alloc.c
View File

@ -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)
@ -2429,10 +2408,8 @@ __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) {