mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
e57b9d8c5a
Commit 682a3385e7 ("mm, page_alloc: inline the fast path of the
zonelist iterator") changed how next_zones_zonelist() is called, by
adding a static inline function to do the fast path. This function
adds:
if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
return z;
return __next_zones_zonelist(z, highest_zoneidx, nodes);
Where __next_zones_zonelist() is only called when nodes is not NULL or
zonelist_zone_idx(z) is less than highest_zoneidx.
The original next_zone_zonelist() was converted to __next_zones_zonelist()
but it still maintained:
if (likely(nodes == NULL))
Which is now actually a very unlikely, as it is only called with nodes
equal to NULL when zonelist_zone_idx(z) is greater than highest_zoneidx.
Before this commit, this if had this statistic:
correct incorrect % Function File Line
------- --------- - -------- ---- ----
837895 446078 34 next_zones_zonelist mmzone.c 63
After this commit, it has:
correct incorrect % Function File Line
------- --------- - -------- ---- ----
10 173840 99 __next_zones_zonelist mmzone.c 63
Thus, the if statement is now much more unlikely than it ever was as a
likely.
Link: http://lkml.kernel.org/r/20170105200102.77989567@gandalf.local.home
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
114 lines
2.4 KiB
C
114 lines
2.4 KiB
C
/*
|
|
* linux/mm/mmzone.c
|
|
*
|
|
* management codes for pgdats, zones and page flags
|
|
*/
|
|
|
|
|
|
#include <linux/stddef.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mmzone.h>
|
|
|
|
struct pglist_data *first_online_pgdat(void)
|
|
{
|
|
return NODE_DATA(first_online_node);
|
|
}
|
|
|
|
struct pglist_data *next_online_pgdat(struct pglist_data *pgdat)
|
|
{
|
|
int nid = next_online_node(pgdat->node_id);
|
|
|
|
if (nid == MAX_NUMNODES)
|
|
return NULL;
|
|
return NODE_DATA(nid);
|
|
}
|
|
|
|
/*
|
|
* next_zone - helper magic for for_each_zone()
|
|
*/
|
|
struct zone *next_zone(struct zone *zone)
|
|
{
|
|
pg_data_t *pgdat = zone->zone_pgdat;
|
|
|
|
if (zone < pgdat->node_zones + MAX_NR_ZONES - 1)
|
|
zone++;
|
|
else {
|
|
pgdat = next_online_pgdat(pgdat);
|
|
if (pgdat)
|
|
zone = pgdat->node_zones;
|
|
else
|
|
zone = NULL;
|
|
}
|
|
return zone;
|
|
}
|
|
|
|
static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
return node_isset(zonelist_node_idx(zref), *nodes);
|
|
#else
|
|
return 1;
|
|
#endif /* CONFIG_NUMA */
|
|
}
|
|
|
|
/* Returns the next zone at or below highest_zoneidx in a zonelist */
|
|
struct zoneref *__next_zones_zonelist(struct zoneref *z,
|
|
enum zone_type highest_zoneidx,
|
|
nodemask_t *nodes)
|
|
{
|
|
/*
|
|
* Find the next suitable zone to use for the allocation.
|
|
* Only filter based on nodemask if it's set
|
|
*/
|
|
if (unlikely(nodes == NULL))
|
|
while (zonelist_zone_idx(z) > highest_zoneidx)
|
|
z++;
|
|
else
|
|
while (zonelist_zone_idx(z) > highest_zoneidx ||
|
|
(z->zone && !zref_in_nodemask(z, nodes)))
|
|
z++;
|
|
|
|
return z;
|
|
}
|
|
|
|
#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
|
|
bool memmap_valid_within(unsigned long pfn,
|
|
struct page *page, struct zone *zone)
|
|
{
|
|
if (page_to_pfn(page) != pfn)
|
|
return false;
|
|
|
|
if (page_zone(page) != zone)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
|
|
|
|
void lruvec_init(struct lruvec *lruvec)
|
|
{
|
|
enum lru_list lru;
|
|
|
|
memset(lruvec, 0, sizeof(struct lruvec));
|
|
|
|
for_each_lru(lru)
|
|
INIT_LIST_HEAD(&lruvec->lists[lru]);
|
|
}
|
|
|
|
#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS)
|
|
int page_cpupid_xchg_last(struct page *page, int cpupid)
|
|
{
|
|
unsigned long old_flags, flags;
|
|
int last_cpupid;
|
|
|
|
do {
|
|
old_flags = flags = page->flags;
|
|
last_cpupid = page_cpupid_last(page);
|
|
|
|
flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
|
|
flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
|
|
} while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags));
|
|
|
|
return last_cpupid;
|
|
}
|
|
#endif
|