mm, memory_hotplug: drop zone from build_all_zonelists

build_all_zonelists gets a zone parameter to initialize zone's pagesets.
There is only a single user which gives a non-NULL zone parameter and
that one doesn't really need the rest of the build_all_zonelists (see
commit 6dcd73d7011b ("memory-hotplug: allocate zone's pcp before
onlining pages")).

Therefore remove setup_zone_pageset from build_all_zonelists and call it
from its only user directly.  This will also remove a pointless zonlists
rebuilding which is always good.

Link: http://lkml.kernel.org/r/20170721143915.14161-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index bfdc37b..551f68b 100644 (file)
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -771,7 +771,7 @@ static inline bool is_dev_zone(const struct zone *zone)
 #include <linux/memory_hotplug.h>
 
 extern struct mutex zonelists_mutex;
-void build_all_zonelists(pg_data_t *pgdat, struct zone *zone);
+void build_all_zonelists(pg_data_t *pgdat);
 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
                         int classzone_idx, unsigned int alloc_flags,

diff --git a/init/main.c b/init/main.c
index 8828fc1..a21a1a8 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -542,7 +542,7 @@ asmlinkage __visible void __init start_kernel(void)
        boot_cpu_state_init();
        smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
 
-       build_all_zonelists(NULL, NULL);
+       build_all_zonelists(NULL);
        page_alloc_init();
 
        pr_notice("Kernel command line: %s\n", boot_command_line);

diff --git a/mm/internal.h b/mm/internal.h
index 4ef49fc..781c0d5 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -525,4 +525,5 @@ static inline bool is_migrate_highatomic_page(struct page *page)
        return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
 }
 
+void setup_zone_pageset(struct zone *zone);
 #endif /* __MM_INTERNAL_H */

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 3e69984..c4df7d3 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -929,7 +929,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
        mutex_lock(&zonelists_mutex);
        if (!populated_zone(zone)) {
                need_zonelists_rebuild = 1;
-               build_all_zonelists(NULL, zone);
+               setup_zone_pageset(zone);
        }
 
        ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages,
@@ -950,7 +950,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
        if (onlined_pages) {
                node_states_set_node(nid, &arg);
                if (need_zonelists_rebuild)
-                       build_all_zonelists(NULL, NULL);
+                       build_all_zonelists(NULL);
                else
                        zone_pcp_update(zone);
        }
@@ -1028,7 +1028,7 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
         * to access not-initialized zonelist, build here.
         */
        mutex_lock(&zonelists_mutex);
-       build_all_zonelists(pgdat, NULL);
+       build_all_zonelists(pgdat);
        mutex_unlock(&zonelists_mutex);
 
        /*
@@ -1084,7 +1084,7 @@ int try_online_node(int nid)
 
        if (pgdat->node_zonelists->_zonerefs->zone == NULL) {
                mutex_lock(&zonelists_mutex);
-               build_all_zonelists(NULL, NULL);
+               build_all_zonelists(NULL);
                mutex_unlock(&zonelists_mutex);
        }
 
@@ -1704,7 +1704,7 @@ repeat:
        if (!populated_zone(zone)) {
                zone_pcp_reset(zone);
                mutex_lock(&zonelists_mutex);
-               build_all_zonelists(NULL, NULL);
+               build_all_zonelists(NULL);
                mutex_unlock(&zonelists_mutex);
        } else
                zone_pcp_update(zone);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 94fb437..2523d5b 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5129,7 +5129,6 @@ static void build_zonelists(pg_data_t *pgdat)
 static void setup_pageset(struct per_cpu_pageset *p, unsigned long batch);
 static DEFINE_PER_CPU(struct per_cpu_pageset, boot_pageset);
 static DEFINE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
-static void setup_zone_pageset(struct zone *zone);
 
 /*
  * Global mutex to protect against size modification of zonelists
@@ -5209,20 +5208,14 @@ build_all_zonelists_init(void)
  * Called with zonelists_mutex held always
  * unless system_state == SYSTEM_BOOTING.
  *
- * __ref due to (1) call of __meminit annotated setup_zone_pageset
- * [we're only called with non-NULL zone through __meminit paths] and
- * (2) call of __init annotated helper build_all_zonelists_init
+ * __ref due to call of __init annotated helper build_all_zonelists_init
  * [protected by SYSTEM_BOOTING].
  */
-void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
+void __ref build_all_zonelists(pg_data_t *pgdat)
 {
        if (system_state == SYSTEM_BOOTING) {
                build_all_zonelists_init();
        } else {
-#ifdef CONFIG_MEMORY_HOTPLUG
-               if (zone)
-                       setup_zone_pageset(zone);
-#endif
                /* we have to stop all cpus to guarantee there is no user
                   of zonelist */
                stop_machine_cpuslocked(__build_all_zonelists, pgdat, NULL);
@@ -5496,7 +5489,7 @@ static void __meminit zone_pageset_init(struct zone *zone, int cpu)
        pageset_set_high_and_batch(zone, pcp);
 }
 
-static void __meminit setup_zone_pageset(struct zone *zone)
+void __meminit setup_zone_pageset(struct zone *zone)
 {
        int cpu;
        zone->pageset = alloc_percpu(struct per_cpu_pageset);