Re: [PATCH v4 2/2] mm/page_alloc: integrate classzone_idx and high_zoneidx
From: Baoquan He
Date: Mon Mar 23 2020 - 01:22:10 EST
On 03/23/20 at 01:49pm, js1304@xxxxxxxxx wrote:
> 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.
>
> 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 f3f2648..337b5ec 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -698,13 +698,13 @@ 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
> @@ -782,15 +782,15 @@ 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",
~~~~~~~~~~ this one could be missed.
And I applied this patch series, use 'git grep classzone_idx' to search
any relics, found below classzone_idx leftover in perl script.
[~]$ git grep classzone_idx
Documentation/trace/postprocess/trace-vmscan-postprocess.pl:my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) classzone_idx=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_skipped=([0-9]*) nr_taken=([0-9]*) lru=([a-z_]*)';
Documentation/trace/postprocess/trace-vmscan-postprocess.pl: "isolate_mode", "classzone_idx", "order",
> __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 a5ab297..f2b3b9c 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 827d8a2..80d6424 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;
> @@ -2296,7 +2296,7 @@ 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;
> @@ -2308,7 +2308,7 @@ 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),
> @@ -2364,8 +2364,8 @@ 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
> @@ -2375,7 +2375,7 @@ 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 */
> @@ -2510,16 +2510,16 @@ 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;
> }
>
> @@ -2537,16 +2537,16 @@ 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];
> @@ -2595,16 +2595,16 @@ 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;
> @@ -2612,8 +2612,8 @@ 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()
> @@ -2626,7 +2626,7 @@ 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);
> }
>
> @@ -2647,7 +2647,7 @@ 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 aebaa33..d84b0d9 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -102,10 +102,10 @@ 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.
> @@ -115,12 +115,21 @@ 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).
> @@ -199,7 +208,7 @@ 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 8bdf484..f942969 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -880,13 +880,13 @@ 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 cb2f896..27bacee 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2620,7 +2620,7 @@ 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
> @@ -3488,7 +3488,7 @@ 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;
> @@ -3533,7 +3533,7 @@ 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 */
> @@ -3566,14 +3566,15 @@ 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;
> @@ -3591,22 +3592,23 @@ 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);
> }
>
> @@ -3683,8 +3685,8 @@ 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;
>
> @@ -3739,7 +3741,7 @@ 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
> @@ -3772,7 +3774,7 @@ 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;
> @@ -3931,7 +3933,7 @@ __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;
> @@ -4134,10 +4136,10 @@ 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;
> @@ -4261,12 +4263,12 @@ 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;
> }
> }
> @@ -4401,8 +4403,8 @@ 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);
> @@ -4416,7 +4418,7 @@ 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) {
> @@ -4535,7 +4537,7 @@ __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;
>
> @@ -4622,7 +4624,7 @@ __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 */
> @@ -4756,7 +4758,7 @@ 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);
> @@ -4795,7 +4797,7 @@ 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);
> }
>
> /*
> @@ -6992,7 +6994,7 @@ 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 1c55bf7..d220671 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 dca623d..0616abe 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -3133,8 +3133,8 @@ 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);
> }
> @@ -3387,7 +3387,7 @@ 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;
> @@ -3399,7 +3399,7 @@ 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;
> @@ -3413,9 +3413,9 @@ 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;
> @@ -3425,19 +3425,19 @@ 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.
> */
> @@ -3463,7 +3463,8 @@ 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
> @@ -3485,7 +3486,7 @@ 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;
> }
> @@ -3549,7 +3550,7 @@ 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;
> @@ -3577,7 +3578,7 @@ 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;
> @@ -3595,7 +3596,7 @@ 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
> @@ -3625,7 +3626,7 @@ 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;
> @@ -3725,7 +3726,7 @@ 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;
>
> @@ -3740,7 +3741,7 @@ 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);
> @@ -3758,22 +3759,22 @@ 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);
> @@ -3790,7 +3791,7 @@ 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.
> @@ -3803,18 +3804,19 @@ 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);
> @@ -3829,7 +3831,7 @@ 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);
>
> /*
> @@ -3871,7 +3873,7 @@ 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);
> @@ -3895,22 +3897,24 @@ 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())
> @@ -3931,9 +3935,10 @@ 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;
> }
> @@ -3951,7 +3956,7 @@ 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;
> @@ -3963,10 +3968,10 @@ 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);
> @@ -3976,8 +3981,8 @@ 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
> @@ -3986,11 +3991,11 @@ 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
>
>