[PATCH v5 2/2] mm/page_alloc: integrate classzone_idx and high_zoneidx

From: js1304
Date: Thu Apr 16 2020 - 23:59:23 EST


From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

classzone_idx is just different name for high_zoneidx now.
So, integrate them and add some comment to struct alloc_context
in order to reduce future confusion about the meaning of this variable.

The accessor, ac_classzone_idx() is also removed since it isn't needed
after integration.

In addition to integration, this patch also renames high_zoneidx
to highest_zoneidx since it represents more precise meaning.

Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
include/linux/compaction.h | 9 ++--
include/linux/mmzone.h | 12 ++---
include/trace/events/compaction.h | 22 ++++----
include/trace/events/vmscan.h | 14 +++--
mm/compaction.c | 64 +++++++++++------------
mm/internal.h | 21 +++++---
mm/memory_hotplug.c | 6 +--
mm/oom_kill.c | 4 +-
mm/page_alloc.c | 60 +++++++++++-----------
mm/slab.c | 4 +-
mm/slub.c | 4 +-
mm/vmscan.c | 105 ++++++++++++++++++++------------------
12 files changed, 175 insertions(+), 150 deletions(-)

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 4b898cd..3ed2f22 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -97,7 +97,7 @@ extern enum compact_result try_to_compact_pages(gfp_t gfp_mask,
struct page **page);
extern void reset_isolation_suitable(pg_data_t *pgdat);
extern enum compact_result compaction_suitable(struct zone *zone, int order,
- unsigned int alloc_flags, int classzone_idx);
+ unsigned int alloc_flags, int highest_zoneidx);

extern void defer_compaction(struct zone *zone, int order);
extern bool compaction_deferred(struct zone *zone, int order);
@@ -182,7 +182,7 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,

extern int kcompactd_run(int nid);
extern void kcompactd_stop(int nid);
-extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
+extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int highest_zoneidx);

#else
static inline void reset_isolation_suitable(pg_data_t *pgdat)
@@ -190,7 +190,7 @@ static inline void reset_isolation_suitable(pg_data_t *pgdat)
}

static inline enum compact_result compaction_suitable(struct zone *zone, int order,
- int alloc_flags, int classzone_idx)
+ int alloc_flags, int highest_zoneidx)
{
return COMPACT_SKIPPED;
}
@@ -232,7 +232,8 @@ static inline void kcompactd_stop(int nid)
{
}

-static inline void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
+static inline void wakeup_kcompactd(pg_data_t *pgdat,
+ int order, int highest_zoneidx)
{
}

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 1b9de7d..7c9b718 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -697,13 +697,13 @@ typedef struct pglist_data {
struct task_struct *kswapd; /* Protected by
mem_hotplug_begin/end() */
int kswapd_order;
- enum zone_type kswapd_classzone_idx;
+ enum zone_type kswapd_highest_zoneidx;

int kswapd_failures; /* Number of 'reclaimed == 0' runs */

#ifdef CONFIG_COMPACTION
int kcompactd_max_order;
- enum zone_type kcompactd_classzone_idx;
+ enum zone_type kcompactd_highest_zoneidx;
wait_queue_head_t kcompactd_wait;
struct task_struct *kcompactd;
#endif
@@ -781,15 +781,15 @@ static inline bool pgdat_is_empty(pg_data_t *pgdat)

void build_all_zonelists(pg_data_t *pgdat);
void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
- enum zone_type classzone_idx);
+ enum zone_type highest_zoneidx);
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
- int classzone_idx, unsigned int alloc_flags,
+ int highest_zoneidx, unsigned int alloc_flags,
long free_pages);
bool zone_watermark_ok(struct zone *z, unsigned int order,
- unsigned long mark, int classzone_idx,
+ unsigned long mark, int highest_zoneidx,
unsigned int alloc_flags);
bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
- unsigned long mark, int classzone_idx);
+ unsigned long mark, int highest_zoneidx);
enum memmap_context {
MEMMAP_EARLY,
MEMMAP_HOTPLUG,
diff --git a/include/trace/events/compaction.h b/include/trace/events/compaction.h
index e5bf6ee..54e5bf0 100644
--- a/include/trace/events/compaction.h
+++ b/include/trace/events/compaction.h
@@ -314,40 +314,44 @@ TRACE_EVENT(mm_compaction_kcompactd_sleep,

DECLARE_EVENT_CLASS(kcompactd_wake_template,

- TP_PROTO(int nid, int order, enum zone_type classzone_idx),
+ TP_PROTO(int nid, int order, enum zone_type highest_zoneidx),

- TP_ARGS(nid, order, classzone_idx),
+ TP_ARGS(nid, order, highest_zoneidx),

TP_STRUCT__entry(
__field(int, nid)
__field(int, order)
- __field(enum zone_type, classzone_idx)
+ __field(enum zone_type, highest_zoneidx)
),

TP_fast_assign(
__entry->nid = nid;
__entry->order = order;
- __entry->classzone_idx = classzone_idx;
+ __entry->highest_zoneidx = highest_zoneidx;
),

+ /*
+ * classzone_idx is previous name of the highest_zoneidx.
+ * Reason not to change it is the ABI requirement of the tracepoint.
+ */
TP_printk("nid=%d order=%d classzone_idx=%-8s",
__entry->nid,
__entry->order,
- __print_symbolic(__entry->classzone_idx, ZONE_TYPE))
+ __print_symbolic(__entry->highest_zoneidx, ZONE_TYPE))
);

DEFINE_EVENT(kcompactd_wake_template, mm_compaction_wakeup_kcompactd,

- TP_PROTO(int nid, int order, enum zone_type classzone_idx),
+ TP_PROTO(int nid, int order, enum zone_type highest_zoneidx),

- TP_ARGS(nid, order, classzone_idx)
+ TP_ARGS(nid, order, highest_zoneidx)
);

DEFINE_EVENT(kcompactd_wake_template, mm_compaction_kcompactd_wake,

- TP_PROTO(int nid, int order, enum zone_type classzone_idx),
+ TP_PROTO(int nid, int order, enum zone_type highest_zoneidx),

- TP_ARGS(nid, order, classzone_idx)
+ TP_ARGS(nid, order, highest_zoneidx)
);
#endif

diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h
index 74bb594..2070df6 100644
--- a/include/trace/events/vmscan.h
+++ b/include/trace/events/vmscan.h
@@ -265,7 +265,7 @@ TRACE_EVENT(mm_shrink_slab_end,
);

TRACE_EVENT(mm_vmscan_lru_isolate,
- TP_PROTO(int classzone_idx,
+ TP_PROTO(int highest_zoneidx,
int order,
unsigned long nr_requested,
unsigned long nr_scanned,
@@ -274,10 +274,10 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
isolate_mode_t isolate_mode,
int lru),

- TP_ARGS(classzone_idx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, isolate_mode, lru),
+ TP_ARGS(highest_zoneidx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, isolate_mode, lru),

TP_STRUCT__entry(
- __field(int, classzone_idx)
+ __field(int, highest_zoneidx)
__field(int, order)
__field(unsigned long, nr_requested)
__field(unsigned long, nr_scanned)
@@ -288,7 +288,7 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
),

TP_fast_assign(
- __entry->classzone_idx = classzone_idx;
+ __entry->highest_zoneidx = highest_zoneidx;
__entry->order = order;
__entry->nr_requested = nr_requested;
__entry->nr_scanned = nr_scanned;
@@ -298,9 +298,13 @@ TRACE_EVENT(mm_vmscan_lru_isolate,
__entry->lru = lru;
),

+ /*
+ * classzone is previous name of the highest_zoneidx.
+ * Reason not to change it is the ABI requirement of the tracepoint.
+ */
TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_skipped=%lu nr_taken=%lu lru=%s",
__entry->isolate_mode,
- __entry->classzone_idx,
+ __entry->highest_zoneidx,
__entry->order,
__entry->nr_requested,
__entry->nr_scanned,
diff --git a/mm/compaction.c b/mm/compaction.c
index 46f0fcc..18079fd 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1966,7 +1966,7 @@ static enum compact_result compact_finished(struct compact_control *cc)
*/
static enum compact_result __compaction_suitable(struct zone *zone, int order,
unsigned int alloc_flags,
- int classzone_idx,
+ int highest_zoneidx,
unsigned long wmark_target)
{
unsigned long watermark;
@@ -1979,7 +1979,7 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,
* If watermarks for high-order allocation are already met, there
* should be no need for compaction at all.
*/
- if (zone_watermark_ok(zone, order, watermark, classzone_idx,
+ if (zone_watermark_ok(zone, order, watermark, highest_zoneidx,
alloc_flags))
return COMPACT_SUCCESS;

@@ -1989,9 +1989,9 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,
* watermark and alloc_flags have to match, or be more pessimistic than
* the check in __isolate_free_page(). We don't use the direct
* compactor's alloc_flags, as they are not relevant for freepage
- * isolation. We however do use the direct compactor's classzone_idx to
- * skip over zones where lowmem reserves would prevent allocation even
- * if compaction succeeds.
+ * isolation. We however do use the direct compactor's highest_zoneidx
+ * to skip over zones where lowmem reserves would prevent allocation
+ * even if compaction succeeds.
* For costly orders, we require low watermark instead of min for
* compaction to proceed to increase its chances.
* ALLOC_CMA is used, as pages in CMA pageblocks are considered
@@ -2000,7 +2000,7 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,
watermark = (order > PAGE_ALLOC_COSTLY_ORDER) ?
low_wmark_pages(zone) : min_wmark_pages(zone);
watermark += compact_gap(order);
- if (!__zone_watermark_ok(zone, 0, watermark, classzone_idx,
+ if (!__zone_watermark_ok(zone, 0, watermark, highest_zoneidx,
ALLOC_CMA, wmark_target))
return COMPACT_SKIPPED;

@@ -2009,12 +2009,12 @@ static enum compact_result __compaction_suitable(struct zone *zone, int order,

enum compact_result compaction_suitable(struct zone *zone, int order,
unsigned int alloc_flags,
- int classzone_idx)
+ int highest_zoneidx)
{
enum compact_result ret;
int fragindex;

- ret = __compaction_suitable(zone, order, alloc_flags, classzone_idx,
+ ret = __compaction_suitable(zone, order, alloc_flags, highest_zoneidx,
zone_page_state(zone, NR_FREE_PAGES));
/*
* fragmentation index determines if allocation failures are due to
@@ -2055,8 +2055,8 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
* Make sure at least one zone would pass __compaction_suitable if we continue
* retrying the reclaim.
*/
- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
- ac->nodemask) {
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->highest_zoneidx, ac->nodemask) {
unsigned long available;
enum compact_result compact_result;

@@ -2069,7 +2069,7 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
available = zone_reclaimable_pages(zone) / order;
available += zone_page_state_snapshot(zone, NR_FREE_PAGES);
compact_result = __compaction_suitable(zone, order, alloc_flags,
- ac_classzone_idx(ac), available);
+ ac->highest_zoneidx, available);
if (compact_result != COMPACT_SKIPPED)
return true;
}
@@ -2100,7 +2100,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)

cc->migratetype = gfpflags_to_migratetype(cc->gfp_mask);
ret = compaction_suitable(cc->zone, cc->order, cc->alloc_flags,
- cc->classzone_idx);
+ cc->highest_zoneidx);
/* Compaction is likely to fail */
if (ret == COMPACT_SUCCESS || ret == COMPACT_SKIPPED)
return ret;
@@ -2295,7 +2295,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)

static enum compact_result compact_zone_order(struct zone *zone, int order,
gfp_t gfp_mask, enum compact_priority prio,
- unsigned int alloc_flags, int classzone_idx,
+ unsigned int alloc_flags, int highest_zoneidx,
struct page **capture)
{
enum compact_result ret;
@@ -2307,7 +2307,7 @@ static enum compact_result compact_zone_order(struct zone *zone, int order,
.mode = (prio == COMPACT_PRIO_ASYNC) ?
MIGRATE_ASYNC : MIGRATE_SYNC_LIGHT,
.alloc_flags = alloc_flags,
- .classzone_idx = classzone_idx,
+ .highest_zoneidx = highest_zoneidx,
.direct_compaction = true,
.whole_zone = (prio == MIN_COMPACT_PRIORITY),
.ignore_skip_hint = (prio == MIN_COMPACT_PRIORITY),
@@ -2363,8 +2363,8 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
trace_mm_compaction_try_to_compact_pages(order, gfp_mask, prio);

/* Compact each zone in the list */
- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
- ac->nodemask) {
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->highest_zoneidx, ac->nodemask) {
enum compact_result status;

if (prio > MIN_COMPACT_PRIORITY
@@ -2374,7 +2374,7 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
}

status = compact_zone_order(zone, order, gfp_mask, prio,
- alloc_flags, ac_classzone_idx(ac), capture);
+ alloc_flags, ac->highest_zoneidx, capture);
rc = max(status, rc);

/* The allocation should succeed, stop compacting */
@@ -2509,16 +2509,16 @@ static bool kcompactd_node_suitable(pg_data_t *pgdat)
{
int zoneid;
struct zone *zone;
- enum zone_type classzone_idx = pgdat->kcompactd_classzone_idx;
+ enum zone_type highest_zoneidx = pgdat->kcompactd_highest_zoneidx;

- for (zoneid = 0; zoneid <= classzone_idx; zoneid++) {
+ for (zoneid = 0; zoneid <= highest_zoneidx; zoneid++) {
zone = &pgdat->node_zones[zoneid];

if (!populated_zone(zone))
continue;

if (compaction_suitable(zone, pgdat->kcompactd_max_order, 0,
- classzone_idx) == COMPACT_CONTINUE)
+ highest_zoneidx) == COMPACT_CONTINUE)
return true;
}

@@ -2536,16 +2536,16 @@ static void kcompactd_do_work(pg_data_t *pgdat)
struct compact_control cc = {
.order = pgdat->kcompactd_max_order,
.search_order = pgdat->kcompactd_max_order,
- .classzone_idx = pgdat->kcompactd_classzone_idx,
+ .highest_zoneidx = pgdat->kcompactd_highest_zoneidx,
.mode = MIGRATE_SYNC_LIGHT,
.ignore_skip_hint = false,
.gfp_mask = GFP_KERNEL,
};
trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order,
- cc.classzone_idx);
+ cc.highest_zoneidx);
count_compact_event(KCOMPACTD_WAKE);

- for (zoneid = 0; zoneid <= cc.classzone_idx; zoneid++) {
+ for (zoneid = 0; zoneid <= cc.highest_zoneidx; zoneid++) {
int status;

zone = &pgdat->node_zones[zoneid];
@@ -2594,16 +2594,16 @@ static void kcompactd_do_work(pg_data_t *pgdat)

/*
* Regardless of success, we are done until woken up next. But remember
- * the requested order/classzone_idx in case it was higher/tighter than
- * our current ones
+ * the requested order/highest_zoneidx in case it was higher/tighter
+ * than our current ones
*/
if (pgdat->kcompactd_max_order <= cc.order)
pgdat->kcompactd_max_order = 0;
- if (pgdat->kcompactd_classzone_idx >= cc.classzone_idx)
- pgdat->kcompactd_classzone_idx = pgdat->nr_zones - 1;
+ if (pgdat->kcompactd_highest_zoneidx >= cc.highest_zoneidx)
+ pgdat->kcompactd_highest_zoneidx = pgdat->nr_zones - 1;
}

-void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
+void wakeup_kcompactd(pg_data_t *pgdat, int order, int highest_zoneidx)
{
if (!order)
return;
@@ -2611,8 +2611,8 @@ void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
if (pgdat->kcompactd_max_order < order)
pgdat->kcompactd_max_order = order;

- if (pgdat->kcompactd_classzone_idx > classzone_idx)
- pgdat->kcompactd_classzone_idx = classzone_idx;
+ if (pgdat->kcompactd_highest_zoneidx > highest_zoneidx)
+ pgdat->kcompactd_highest_zoneidx = highest_zoneidx;

/*
* Pairs with implicit barrier in wait_event_freezable()
@@ -2625,7 +2625,7 @@ void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx)
return;

trace_mm_compaction_wakeup_kcompactd(pgdat->node_id, order,
- classzone_idx);
+ highest_zoneidx);
wake_up_interruptible(&pgdat->kcompactd_wait);
}

@@ -2646,7 +2646,7 @@ static int kcompactd(void *p)
set_freezable();

pgdat->kcompactd_max_order = 0;
- pgdat->kcompactd_classzone_idx = pgdat->nr_zones - 1;
+ pgdat->kcompactd_highest_zoneidx = pgdat->nr_zones - 1;

while (!kthread_should_stop()) {
unsigned long pflags;
diff --git a/mm/internal.h b/mm/internal.h
index 0ab58df..ee63051 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -125,10 +125,10 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
* between functions involved in allocations, including the alloc_pages*
* family of functions.
*
- * nodemask, migratetype and high_zoneidx are initialized only once in
+ * nodemask, migratetype and highest_zoneidx are initialized only once in
* __alloc_pages_nodemask() and then never change.
*
- * zonelist, preferred_zone and classzone_idx are set first in
+ * zonelist, preferred_zone and highest_zoneidx 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.
@@ -138,12 +138,21 @@ struct alloc_context {
nodemask_t *nodemask;
struct zoneref *preferred_zoneref;
int migratetype;
- enum zone_type high_zoneidx;
+
+ /*
+ * highest_zoneidx represents highest usable zone index of
+ * the allocation request. Due to the nature of the zone,
+ * memory on lower zone than the highest_zoneidx will be
+ * protected by lowmem_reserve[highest_zoneidx].
+ *
+ * highest_zoneidx is also used by reclaim/compaction to limit
+ * the target zone since higher zone than this index cannot be
+ * usable for this allocation request.
+ */
+ enum zone_type highest_zoneidx;
bool spread_dirty_pages;
};

-#define ac_classzone_idx(ac) (ac->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).
@@ -222,7 +231,7 @@ struct compact_control {
int order; /* order a direct compactor needs */
int migratetype; /* migratetype of direct compactor */
const unsigned int alloc_flags; /* alloc flags of a direct compactor */
- const int classzone_idx; /* zone index of a direct compactor */
+ const int highest_zoneidx; /* zone index of a direct compactor */
enum migrate_mode mode; /* Async or sync migration mode */
bool ignore_skip_hint; /* Scan blocks even if marked skip */
bool no_set_skip_hint; /* Don't mark blocks for skipping */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 47cf603..c550b5c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -883,13 +883,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
} else {
int cpu;
/*
- * Reset the nr_zones, order and classzone_idx before reuse.
- * Note that kswapd will init kswapd_classzone_idx properly
+ * Reset the nr_zones, order and highest_zoneidx before reuse.
+ * Note that kswapd will init kswapd_highest_zoneidx properly
* when it starts in the near future.
*/
pgdat->nr_zones = 0;
pgdat->kswapd_order = 0;
- pgdat->kswapd_classzone_idx = 0;
+ pgdat->kswapd_highest_zoneidx = 0;
for_each_online_cpu(cpu) {
struct per_cpu_nodestat *p;

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index dfc3576..4daedf7 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -254,7 +254,7 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)
{
struct zone *zone;
struct zoneref *z;
- enum zone_type high_zoneidx = gfp_zone(oc->gfp_mask);
+ enum zone_type highest_zoneidx = gfp_zone(oc->gfp_mask);
bool cpuset_limited = false;
int nid;

@@ -294,7 +294,7 @@ static enum oom_constraint constrained_alloc(struct oom_control *oc)

/* Check this allocation failure is caused by cpuset's wall function */
for_each_zone_zonelist_nodemask(zone, z, oc->zonelist,
- high_zoneidx, oc->nodemask)
+ highest_zoneidx, oc->nodemask)
if (!cpuset_zone_allowed(zone, oc->gfp_mask))
cpuset_limited = true;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1385d78..fcf134e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2600,7 +2600,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
int order;
bool ret;

- for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->high_zoneidx,
+ for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
ac->nodemask) {
/*
* Preserve at least one pageblock unless memory pressure
@@ -3469,7 +3469,7 @@ ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
* to check in the allocation paths if no pages are free.
*/
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
- int classzone_idx, unsigned int alloc_flags,
+ int highest_zoneidx, unsigned int alloc_flags,
long free_pages)
{
long min = mark;
@@ -3514,7 +3514,7 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
* are not met, then a high-order request also cannot go ahead
* even if a suitable page happened to be free.
*/
- if (free_pages <= min + z->lowmem_reserve[classzone_idx])
+ if (free_pages <= min + z->lowmem_reserve[highest_zoneidx])
return false;

/* If this is an order-0 request then the watermark is fine */
@@ -3547,14 +3547,15 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
}

bool zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
- int classzone_idx, unsigned int alloc_flags)
+ int highest_zoneidx, unsigned int alloc_flags)
{
- return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+ return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
zone_page_state(z, NR_FREE_PAGES));
}

static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
- unsigned long mark, int classzone_idx, unsigned int alloc_flags)
+ unsigned long mark, int highest_zoneidx,
+ unsigned int alloc_flags)
{
long free_pages = zone_page_state(z, NR_FREE_PAGES);
long cma_pages = 0;
@@ -3572,22 +3573,23 @@ static inline bool zone_watermark_fast(struct zone *z, unsigned int order,
* the caller is !atomic then it'll uselessly search the free
* list. That corner case is then slower but it is harmless.
*/
- if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx])
+ if (!order && (free_pages - cma_pages) >
+ mark + z->lowmem_reserve[highest_zoneidx])
return true;

- return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags,
+ return __zone_watermark_ok(z, order, mark, highest_zoneidx, alloc_flags,
free_pages);
}

bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
- unsigned long mark, int classzone_idx)
+ unsigned long mark, int highest_zoneidx)
{
long free_pages = zone_page_state(z, NR_FREE_PAGES);

if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark)
free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES);

- return __zone_watermark_ok(z, order, mark, classzone_idx, 0,
+ return __zone_watermark_ok(z, order, mark, highest_zoneidx, 0,
free_pages);
}

@@ -3664,8 +3666,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
*/
no_fallback = alloc_flags & ALLOC_NOFRAGMENT;
z = ac->preferred_zoneref;
- for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
- ac->nodemask) {
+ for_next_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->highest_zoneidx, ac->nodemask) {
struct page *page;
unsigned long mark;

@@ -3720,7 +3722,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,

mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
if (!zone_watermark_fast(zone, order, mark,
- ac_classzone_idx(ac), alloc_flags)) {
+ ac->highest_zoneidx, alloc_flags)) {
int ret;

#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
@@ -3753,7 +3755,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
default:
/* did we reclaim enough */
if (zone_watermark_ok(zone, order, mark,
- ac_classzone_idx(ac), alloc_flags))
+ ac->highest_zoneidx, alloc_flags))
goto try_this_zone;

continue;
@@ -3912,7 +3914,7 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order,
if (gfp_mask & __GFP_RETRY_MAYFAIL)
goto out;
/* The OOM killer does not needlessly kill tasks for lowmem */
- if (ac->high_zoneidx < ZONE_NORMAL)
+ if (ac->highest_zoneidx < ZONE_NORMAL)
goto out;
if (pm_suspended_storage())
goto out;
@@ -4115,10 +4117,10 @@ should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_fla
* Let's give them a good hope and keep retrying while the order-0
* watermarks are OK.
*/
- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
- ac->nodemask) {
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->highest_zoneidx, ac->nodemask) {
if (zone_watermark_ok(zone, 0, min_wmark_pages(zone),
- ac_classzone_idx(ac), alloc_flags))
+ ac->highest_zoneidx, alloc_flags))
return true;
}
return false;
@@ -4242,12 +4244,12 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
struct zoneref *z;
struct zone *zone;
pg_data_t *last_pgdat = NULL;
- enum zone_type high_zoneidx = ac->high_zoneidx;
+ enum zone_type highest_zoneidx = ac->highest_zoneidx;

- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, high_zoneidx,
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
ac->nodemask) {
if (last_pgdat != zone->zone_pgdat)
- wakeup_kswapd(zone, gfp_mask, order, high_zoneidx);
+ wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
last_pgdat = zone->zone_pgdat;
}
}
@@ -4382,8 +4384,8 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
* request even if all reclaimable pages are considered then we are
* screwed and have to go OOM.
*/
- for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
- ac->nodemask) {
+ for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
+ ac->highest_zoneidx, ac->nodemask) {
unsigned long available;
unsigned long reclaimable;
unsigned long min_wmark = min_wmark_pages(zone);
@@ -4397,7 +4399,7 @@ should_reclaim_retry(gfp_t gfp_mask, unsigned order,
* reclaimable pages?
*/
wmark = __zone_watermark_ok(zone, order, min_wmark,
- ac_classzone_idx(ac), alloc_flags, available);
+ ac->highest_zoneidx, alloc_flags, available);
trace_reclaim_retry_zone(z, order, reclaimable,
available, min_wmark, *no_progress_loops, wmark);
if (wmark) {
@@ -4516,7 +4518,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
* could end up iterating over non-eligible zones endlessly.
*/
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
- ac->high_zoneidx, ac->nodemask);
+ ac->highest_zoneidx, ac->nodemask);
if (!ac->preferred_zoneref->zone)
goto nopage;

@@ -4603,7 +4605,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
if (!(alloc_flags & ALLOC_CPUSET) || reserve_flags) {
ac->nodemask = NULL;
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
- ac->high_zoneidx, ac->nodemask);
+ ac->highest_zoneidx, ac->nodemask);
}

/* Attempt with potentially adjusted zonelist and alloc_flags */
@@ -4737,7 +4739,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
struct alloc_context *ac, gfp_t *alloc_mask,
unsigned int *alloc_flags)
{
- ac->high_zoneidx = gfp_zone(gfp_mask);
+ ac->highest_zoneidx = gfp_zone(gfp_mask);
ac->zonelist = node_zonelist(preferred_nid, gfp_mask);
ac->nodemask = nodemask;
ac->migratetype = gfpflags_to_migratetype(gfp_mask);
@@ -4776,7 +4778,7 @@ static inline void finalise_ac(gfp_t gfp_mask, struct alloc_context *ac)
* may get reset for allocations that ignore memory policies.
*/
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
- ac->high_zoneidx, ac->nodemask);
+ ac->highest_zoneidx, ac->nodemask);
}

/*
@@ -6973,7 +6975,7 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
unsigned long end_pfn = 0;

/* pg_data_t should be reset to zero when it's allocated */
- WARN_ON(pgdat->nr_zones || pgdat->kswapd_classzone_idx);
+ WARN_ON(pgdat->nr_zones || pgdat->kswapd_highest_zoneidx);

pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
diff --git a/mm/slab.c b/mm/slab.c
index a896336..9350062 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3106,7 +3106,7 @@ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
struct zonelist *zonelist;
struct zoneref *z;
struct zone *zone;
- enum zone_type high_zoneidx = gfp_zone(flags);
+ enum zone_type highest_zoneidx = gfp_zone(flags);
void *obj = NULL;
struct page *page;
int nid;
@@ -3124,7 +3124,7 @@ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
* Look through allowed nodes for objects available
* from existing per node queues.
*/
- for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+ for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
nid = zone_to_nid(zone);

if (cpuset_zone_allowed(zone, flags) &&
diff --git a/mm/slub.c b/mm/slub.c
index 7002af0..e1321ac 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1909,7 +1909,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
struct zonelist *zonelist;
struct zoneref *z;
struct zone *zone;
- enum zone_type high_zoneidx = gfp_zone(flags);
+ enum zone_type highest_zoneidx = gfp_zone(flags);
void *object;
unsigned int cpuset_mems_cookie;

@@ -1938,7 +1938,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags,
do {
cpuset_mems_cookie = read_mems_allowed_begin();
zonelist = node_zonelist(mempolicy_slab_node(), flags);
- for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+ for_each_zone_zonelist(zone, z, zonelist, highest_zoneidx) {
struct kmem_cache_node *n;

n = get_node(s, zone_to_nid(zone));
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b06868f..5fd58b9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3132,8 +3132,8 @@ static bool allow_direct_reclaim(pg_data_t *pgdat)

/* kswapd must be awake if processes are being throttled */
if (!wmark_ok && waitqueue_active(&pgdat->kswapd_wait)) {
- if (READ_ONCE(pgdat->kswapd_classzone_idx) > ZONE_NORMAL)
- WRITE_ONCE(pgdat->kswapd_classzone_idx, ZONE_NORMAL);
+ if (READ_ONCE(pgdat->kswapd_highest_zoneidx) > ZONE_NORMAL)
+ WRITE_ONCE(pgdat->kswapd_highest_zoneidx, ZONE_NORMAL);

wake_up_interruptible(&pgdat->kswapd_wait);
}
@@ -3386,7 +3386,7 @@ static void age_active_anon(struct pglist_data *pgdat,
} while (memcg);
}

-static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx)
+static bool pgdat_watermark_boosted(pg_data_t *pgdat, int highest_zoneidx)
{
int i;
struct zone *zone;
@@ -3398,7 +3398,7 @@ static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx)
* start prematurely when there is no boosting and a lower
* zone is balanced.
*/
- for (i = classzone_idx; i >= 0; i--) {
+ for (i = highest_zoneidx; i >= 0; i--) {
zone = pgdat->node_zones + i;
if (!managed_zone(zone))
continue;
@@ -3412,9 +3412,9 @@ static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx)

/*
* Returns true if there is an eligible zone balanced for the request order
- * and classzone_idx
+ * and highest_zoneidx
*/
-static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx)
+static bool pgdat_balanced(pg_data_t *pgdat, int order, int highest_zoneidx)
{
int i;
unsigned long mark = -1;
@@ -3424,19 +3424,19 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx)
* Check watermarks bottom-up as lower zones are more likely to
* meet watermarks.
*/
- for (i = 0; i <= classzone_idx; i++) {
+ for (i = 0; i <= highest_zoneidx; i++) {
zone = pgdat->node_zones + i;

if (!managed_zone(zone))
continue;

mark = high_wmark_pages(zone);
- if (zone_watermark_ok_safe(zone, order, mark, classzone_idx))
+ if (zone_watermark_ok_safe(zone, order, mark, highest_zoneidx))
return true;
}

/*
- * If a node has no populated zone within classzone_idx, it does not
+ * If a node has no populated zone within highest_zoneidx, it does not
* need balancing by definition. This can happen if a zone-restricted
* allocation tries to wake a remote kswapd.
*/
@@ -3462,7 +3462,8 @@ static void clear_pgdat_congested(pg_data_t *pgdat)
*
* Returns true if kswapd is ready to sleep
*/
-static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx)
+static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order,
+ int highest_zoneidx)
{
/*
* The throttled processes are normally woken up in balance_pgdat() as
@@ -3484,7 +3485,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx)
if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES)
return true;

- if (pgdat_balanced(pgdat, order, classzone_idx)) {
+ if (pgdat_balanced(pgdat, order, highest_zoneidx)) {
clear_pgdat_congested(pgdat);
return true;
}
@@ -3548,7 +3549,7 @@ static bool kswapd_shrink_node(pg_data_t *pgdat,
* or lower is eligible for reclaim until at least one usable zone is
* balanced.
*/
-static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
+static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx)
{
int i;
unsigned long nr_soft_reclaimed;
@@ -3576,7 +3577,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
* stall or direct reclaim until kswapd is finished.
*/
nr_boost_reclaim = 0;
- for (i = 0; i <= classzone_idx; i++) {
+ for (i = 0; i <= highest_zoneidx; i++) {
zone = pgdat->node_zones + i;
if (!managed_zone(zone))
continue;
@@ -3594,7 +3595,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
bool balanced;
bool ret;

- sc.reclaim_idx = classzone_idx;
+ sc.reclaim_idx = highest_zoneidx;

/*
* If the number of buffer_heads exceeds the maximum allowed
@@ -3624,7 +3625,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
* on the grounds that the normal reclaim should be enough to
* re-evaluate if boosting is required when kswapd next wakes.
*/
- balanced = pgdat_balanced(pgdat, sc.order, classzone_idx);
+ balanced = pgdat_balanced(pgdat, sc.order, highest_zoneidx);
if (!balanced && nr_boost_reclaim) {
nr_boost_reclaim = 0;
goto restart;
@@ -3724,7 +3725,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
if (boosted) {
unsigned long flags;

- for (i = 0; i <= classzone_idx; i++) {
+ for (i = 0; i <= highest_zoneidx; i++) {
if (!zone_boosts[i])
continue;

@@ -3739,7 +3740,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
* As there is now likely space, wakeup kcompact to defragment
* pageblocks.
*/
- wakeup_kcompactd(pgdat, pageblock_order, classzone_idx);
+ wakeup_kcompactd(pgdat, pageblock_order, highest_zoneidx);
}

snapshot_refaults(NULL, pgdat);
@@ -3757,22 +3758,22 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx)
}

/*
- * The pgdat->kswapd_classzone_idx is used to pass the highest zone index to be
- * reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is not
- * a valid index then either kswapd runs for first time or kswapd couldn't sleep
- * after previous reclaim attempt (node is still unbalanced). In that case
- * return the zone index of the previous kswapd reclaim cycle.
+ * The pgdat->kswapd_highest_zoneidx is used to pass the highest zone index to
+ * be reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is
+ * not a valid index then either kswapd runs for first time or kswapd couldn't
+ * sleep after previous reclaim attempt (node is still unbalanced). In that
+ * case return the zone index of the previous kswapd reclaim cycle.
*/
-static enum zone_type kswapd_classzone_idx(pg_data_t *pgdat,
- enum zone_type prev_classzone_idx)
+static enum zone_type kswapd_highest_zoneidx(pg_data_t *pgdat,
+ enum zone_type prev_highest_zoneidx)
{
- enum zone_type curr_idx = READ_ONCE(pgdat->kswapd_classzone_idx);
+ enum zone_type curr_idx = READ_ONCE(pgdat->kswapd_highest_zoneidx);

- return curr_idx == MAX_NR_ZONES ? prev_classzone_idx : curr_idx;
+ return curr_idx == MAX_NR_ZONES ? prev_highest_zoneidx : curr_idx;
}

static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_order,
- unsigned int classzone_idx)
+ unsigned int highest_zoneidx)
{
long remaining = 0;
DEFINE_WAIT(wait);
@@ -3789,7 +3790,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o
* eligible zone balanced that it's also unlikely that compaction will
* succeed.
*/
- if (prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) {
+ if (prepare_kswapd_sleep(pgdat, reclaim_order, highest_zoneidx)) {
/*
* Compaction records what page blocks it recently failed to
* isolate pages from and skips them in the future scanning.
@@ -3802,18 +3803,19 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o
* We have freed the memory, now we should compact it to make
* allocation of the requested order possible.
*/
- wakeup_kcompactd(pgdat, alloc_order, classzone_idx);
+ wakeup_kcompactd(pgdat, alloc_order, highest_zoneidx);

remaining = schedule_timeout(HZ/10);

/*
- * If woken prematurely then reset kswapd_classzone_idx and
+ * If woken prematurely then reset kswapd_highest_zoneidx and
* order. The values will either be from a wakeup request or
* the previous request that slept prematurely.
*/
if (remaining) {
- WRITE_ONCE(pgdat->kswapd_classzone_idx,
- kswapd_classzone_idx(pgdat, classzone_idx));
+ WRITE_ONCE(pgdat->kswapd_highest_zoneidx,
+ kswapd_highest_zoneidx(pgdat,
+ highest_zoneidx));

if (READ_ONCE(pgdat->kswapd_order) < reclaim_order)
WRITE_ONCE(pgdat->kswapd_order, reclaim_order);
@@ -3828,7 +3830,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o
* go fully to sleep until explicitly woken up.
*/
if (!remaining &&
- prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) {
+ prepare_kswapd_sleep(pgdat, reclaim_order, highest_zoneidx)) {
trace_mm_vmscan_kswapd_sleep(pgdat->node_id);

/*
@@ -3870,7 +3872,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o
static int kswapd(void *p)
{
unsigned int alloc_order, reclaim_order;
- unsigned int classzone_idx = MAX_NR_ZONES - 1;
+ unsigned int highest_zoneidx = MAX_NR_ZONES - 1;
pg_data_t *pgdat = (pg_data_t*)p;
struct task_struct *tsk = current;
const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
@@ -3894,22 +3896,24 @@ static int kswapd(void *p)
set_freezable();

WRITE_ONCE(pgdat->kswapd_order, 0);
- WRITE_ONCE(pgdat->kswapd_classzone_idx, MAX_NR_ZONES);
+ WRITE_ONCE(pgdat->kswapd_highest_zoneidx, MAX_NR_ZONES);
for ( ; ; ) {
bool ret;

alloc_order = reclaim_order = READ_ONCE(pgdat->kswapd_order);
- classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx);
+ highest_zoneidx = kswapd_highest_zoneidx(pgdat,
+ highest_zoneidx);

kswapd_try_sleep:
kswapd_try_to_sleep(pgdat, alloc_order, reclaim_order,
- classzone_idx);
+ highest_zoneidx);

- /* Read the new order and classzone_idx */
+ /* Read the new order and highest_zoneidx */
alloc_order = reclaim_order = READ_ONCE(pgdat->kswapd_order);
- classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx);
+ highest_zoneidx = kswapd_highest_zoneidx(pgdat,
+ highest_zoneidx);
WRITE_ONCE(pgdat->kswapd_order, 0);
- WRITE_ONCE(pgdat->kswapd_classzone_idx, MAX_NR_ZONES);
+ WRITE_ONCE(pgdat->kswapd_highest_zoneidx, MAX_NR_ZONES);

ret = try_to_freeze();
if (kthread_should_stop())
@@ -3930,9 +3934,10 @@ static int kswapd(void *p)
* but kcompactd is woken to compact for the original
* request (alloc_order).
*/
- trace_mm_vmscan_kswapd_wake(pgdat->node_id, classzone_idx,
+ trace_mm_vmscan_kswapd_wake(pgdat->node_id, highest_zoneidx,
alloc_order);
- reclaim_order = balance_pgdat(pgdat, alloc_order, classzone_idx);
+ reclaim_order = balance_pgdat(pgdat, alloc_order,
+ highest_zoneidx);
if (reclaim_order < alloc_order)
goto kswapd_try_sleep;
}
@@ -3950,7 +3955,7 @@ static int kswapd(void *p)
* needed.
*/
void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,
- enum zone_type classzone_idx)
+ enum zone_type highest_zoneidx)
{
pg_data_t *pgdat;
enum zone_type curr_idx;
@@ -3962,10 +3967,10 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,
return;

pgdat = zone->zone_pgdat;
- curr_idx = READ_ONCE(pgdat->kswapd_classzone_idx);
+ curr_idx = READ_ONCE(pgdat->kswapd_highest_zoneidx);

- if (curr_idx == MAX_NR_ZONES || curr_idx < classzone_idx)
- WRITE_ONCE(pgdat->kswapd_classzone_idx, classzone_idx);
+ if (curr_idx == MAX_NR_ZONES || curr_idx < highest_zoneidx)
+ WRITE_ONCE(pgdat->kswapd_highest_zoneidx, highest_zoneidx);

if (READ_ONCE(pgdat->kswapd_order) < order)
WRITE_ONCE(pgdat->kswapd_order, order);
@@ -3975,8 +3980,8 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,

/* Hopeless node, leave it to direct reclaim if possible */
if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ||
- (pgdat_balanced(pgdat, order, classzone_idx) &&
- !pgdat_watermark_boosted(pgdat, classzone_idx))) {
+ (pgdat_balanced(pgdat, order, highest_zoneidx) &&
+ !pgdat_watermark_boosted(pgdat, highest_zoneidx))) {
/*
* There may be plenty of free memory available, but it's too
* fragmented for high-order allocations. Wake up kcompactd
@@ -3985,11 +3990,11 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order,
* ratelimit its work.
*/
if (!(gfp_flags & __GFP_DIRECT_RECLAIM))
- wakeup_kcompactd(pgdat, order, classzone_idx);
+ wakeup_kcompactd(pgdat, order, highest_zoneidx);
return;
}

- trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, classzone_idx, order,
+ trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, highest_zoneidx, order,
gfp_flags);
wake_up_interruptible(&pgdat->kswapd_wait);
}
--
2.7.4