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mm: clean up zone flags

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Page reclaim tests zone_is_reclaim_dirty(), but the site that actually
sets this state does zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY), sending the
reader through layers indirection just to track down a simple bit.

Remove all zone flag wrappers and just use bitops against zone->flags
directly.  It's just as readable and the lines are barely any longer.

Also rename ZONE_TAIL_LRU_DIRTY to ZONE_DIRTY to match ZONE_WRITEBACK, and
remove the zone_flags_t typedef.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2014-10-09 15:28:17 -07:00 committed by Linus Torvalds
parent 7c809968ff
commit 5705465174
5 changed files with 25 additions and 70 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
include/linux/mmzone.h
View File

@ -521,13 +521,13 @@ struct zone {
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
} ____cacheline_internodealigned_in_smp;
typedef enum {
enum zone_flags {
ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
ZONE_CONGESTED, /* zone has many dirty pages backed by
* a congested BDI
*/
ZONE_TAIL_LRU_DIRTY, /* reclaim scanning has recently found
ZONE_DIRTY, /* reclaim scanning has recently found
* many dirty file pages at the tail
* of the LRU.
*/
@ -535,52 +535,7 @@ typedef enum {
* many pages under writeback
*/
ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */
} zone_flags_t;
static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
{
set_bit(flag, &zone->flags);
}
static inline int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
{
return test_and_set_bit(flag, &zone->flags);
}
static inline void zone_clear_flag(struct zone *zone, zone_flags_t flag)
{
clear_bit(flag, &zone->flags);
}
static inline int zone_is_reclaim_congested(const struct zone *zone)
{
return test_bit(ZONE_CONGESTED, &zone->flags);
}
static inline int zone_is_reclaim_dirty(const struct zone *zone)
{
return test_bit(ZONE_TAIL_LRU_DIRTY, &zone->flags);
}
static inline int zone_is_reclaim_writeback(const struct zone *zone)
{
return test_bit(ZONE_WRITEBACK, &zone->flags);
}
static inline int zone_is_reclaim_locked(const struct zone *zone)
{
return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
}
static inline int zone_is_fair_depleted(const struct zone *zone)
{
return test_bit(ZONE_FAIR_DEPLETED, &zone->flags);
}
static inline int zone_is_oom_locked(const struct zone *zone)
{
return test_bit(ZONE_OOM_LOCKED, &zone->flags);
}
};
static inline unsigned long zone_end_pfn(const struct zone *zone)
{

2
mm/backing-dev.c
View File

@ -631,7 +631,7 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout)
* of sleeping on the congestion queue
*/
if (atomic_read(&nr_bdi_congested[sync]) == 0 ||
!zone_is_reclaim_congested(zone)) {
!test_bit(ZONE_CONGESTED, &zone->flags)) {
cond_resched();
/* In case we scheduled, work out time remaining */

6
mm/oom_kill.c
View File

@ -565,7 +565,7 @@ bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask)
spin_lock(&zone_scan_lock);
for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
if (zone_is_oom_locked(zone)) {
if (test_bit(ZONE_OOM_LOCKED, &zone->flags)) {
ret = false;
goto out;
}
@ -575,7 +575,7 @@ bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_mask)
* call to oom_zonelist_trylock() doesn't succeed when it shouldn't.
*/
for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
zone_set_flag(zone, ZONE_OOM_LOCKED);
set_bit(ZONE_OOM_LOCKED, &zone->flags);
out:
spin_unlock(&zone_scan_lock);
@ -594,7 +594,7 @@ void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_mask)
spin_lock(&zone_scan_lock);
for_each_zone_zonelist(zone, z, zonelist, gfp_zone(gfp_mask))
zone_clear_flag(zone, ZONE_OOM_LOCKED);
clear_bit(ZONE_OOM_LOCKED, &zone->flags);
spin_unlock(&zone_scan_lock);
}

8
mm/page_alloc.c
View File

@ -1614,8 +1614,8 @@ again:
__mod_zone_page_state(zone, NR_ALLOC_BATCH, -(1 << order));
if (atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]) <= 0 &&
!zone_is_fair_depleted(zone))
zone_set_flag(zone, ZONE_FAIR_DEPLETED);
!test_bit(ZONE_FAIR_DEPLETED, &zone->flags))
set_bit(ZONE_FAIR_DEPLETED, &zone->flags);
__count_zone_vm_events(PGALLOC, zone, 1 << order);
zone_statistics(preferred_zone, zone, gfp_flags);
@ -1935,7 +1935,7 @@ static void reset_alloc_batches(struct zone *preferred_zone)
mod_zone_page_state(zone, NR_ALLOC_BATCH,
high_wmark_pages(zone) - low_wmark_pages(zone) -
atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH]));
zone_clear_flag(zone, ZONE_FAIR_DEPLETED);
clear_bit(ZONE_FAIR_DEPLETED, &zone->flags);
} while (zone++ != preferred_zone);
}
@ -1986,7 +1986,7 @@ zonelist_scan:
if (alloc_flags & ALLOC_FAIR) {
if (!zone_local(preferred_zone, zone))
break;
if (zone_is_fair_depleted(zone)) {
if (test_bit(ZONE_FAIR_DEPLETED, &zone->flags)) {
nr_fair_skipped++;
continue;
}

28
mm/vmscan.c
View File

@ -920,7 +920,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
/* Case 1 above */
if (current_is_kswapd() &&
PageReclaim(page) &&
zone_is_reclaim_writeback(zone)) {
test_bit(ZONE_WRITEBACK, &zone->flags)) {
nr_immediate++;
goto keep_locked;
@ -1002,7 +1002,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
*/
if (page_is_file_cache(page) &&
(!current_is_kswapd() ||
!zone_is_reclaim_dirty(zone))) {
!test_bit(ZONE_DIRTY, &zone->flags))) {
/*
* Immediately reclaim when written back.
* Similar in principal to deactivate_page()
@ -1563,7 +1563,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
* are encountered in the nr_immediate check below.
*/
if (nr_writeback && nr_writeback == nr_taken)
zone_set_flag(zone, ZONE_WRITEBACK);
set_bit(ZONE_WRITEBACK, &zone->flags);
/*
* memcg will stall in page writeback so only consider forcibly
@ -1575,16 +1575,16 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
* backed by a congested BDI and wait_iff_congested will stall.
*/
if (nr_dirty && nr_dirty == nr_congested)
zone_set_flag(zone, ZONE_CONGESTED);
set_bit(ZONE_CONGESTED, &zone->flags);
/*
* If dirty pages are scanned that are not queued for IO, it
* implies that flushers are not keeping up. In this case, flag
* the zone ZONE_TAIL_LRU_DIRTY and kswapd will start writing
* pages from reclaim context.
* the zone ZONE_DIRTY and kswapd will start writing pages from
* reclaim context.
*/
if (nr_unqueued_dirty == nr_taken)
zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY);
set_bit(ZONE_DIRTY, &zone->flags);
/*
* If kswapd scans pages marked marked for immediate
@ -2984,7 +2984,7 @@ static bool kswapd_shrink_zone(struct zone *zone,
/* Account for the number of pages attempted to reclaim */
*nr_attempted += sc->nr_to_reclaim;
zone_clear_flag(zone, ZONE_WRITEBACK);
clear_bit(ZONE_WRITEBACK, &zone->flags);
/*
* If a zone reaches its high watermark, consider it to be no longer
@ -2994,8 +2994,8 @@ static bool kswapd_shrink_zone(struct zone *zone,
*/
if (zone_reclaimable(zone) &&
zone_balanced(zone, testorder, 0, classzone_idx)) {
zone_clear_flag(zone, ZONE_CONGESTED);
zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
clear_bit(ZONE_CONGESTED, &zone->flags);
clear_bit(ZONE_DIRTY, &zone->flags);
}
return sc->nr_scanned >= sc->nr_to_reclaim;
@ -3086,8 +3086,8 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
* If balanced, clear the dirty and congested
* flags
*/
zone_clear_flag(zone, ZONE_CONGESTED);
zone_clear_flag(zone, ZONE_TAIL_LRU_DIRTY);
clear_bit(ZONE_CONGESTED, &zone->flags);
clear_bit(ZONE_DIRTY, &zone->flags);
}
}
@ -3714,11 +3714,11 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
if (node_state(node_id, N_CPU) && node_id != numa_node_id())
return ZONE_RECLAIM_NOSCAN;
if (zone_test_and_set_flag(zone, ZONE_RECLAIM_LOCKED))
if (test_and_set_bit(ZONE_RECLAIM_LOCKED, &zone->flags))
return ZONE_RECLAIM_NOSCAN;
ret = __zone_reclaim(zone, gfp_mask, order);
zone_clear_flag(zone, ZONE_RECLAIM_LOCKED);
clear_bit(ZONE_RECLAIM_LOCKED, &zone->flags);
if (!ret)
count_vm_event(PGSCAN_ZONE_RECLAIM_FAILED);