Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...

1 files changed, 29 insertions, 0 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 0b6480979ac7..a749d4d96e3e 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -170,6 +170,14 @@ static LIST_HEAD(pcpu_map_extend_chunks);
 int pcpu_nr_empty_pop_pages;
 
 /*
+ * The number of populated pages in use by the allocator, protected by
+ * pcpu_lock.  This number is kept per a unit per chunk (i.e. when a page gets
+ * allocated/deallocated, it is allocated/deallocated in all units of a chunk
+ * and increments/decrements this count by 1).
+ */
+static unsigned long pcpu_nr_populated;
+
+/*
  * Balance work is used to populate or destroy chunks asynchronously.  We
  * try to keep the number of populated free pages between
  * PCPU_EMPTY_POP_PAGES_LOW and HIGH for atomic allocations and at most one
@@ -1232,6 +1240,7 @@ static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start,
 
 	bitmap_set(chunk->populated, page_start, nr);
 	chunk->nr_populated += nr;
+	pcpu_nr_populated += nr;
 
 	if (!for_alloc) {
 		chunk->nr_empty_pop_pages += nr;
@@ -1260,6 +1269,7 @@ static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk,
 	chunk->nr_populated -= nr;
 	chunk->nr_empty_pop_pages -= nr;
 	pcpu_nr_empty_pop_pages -= nr;
+	pcpu_nr_populated -= nr;
 }
 
 /*
@@ -2176,6 +2186,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 	pcpu_nr_empty_pop_pages = pcpu_first_chunk->nr_empty_pop_pages;
 	pcpu_chunk_relocate(pcpu_first_chunk, -1);
 
+	/* include all regions of the first chunk */
+	pcpu_nr_populated += PFN_DOWN(size_sum);
+
 	pcpu_stats_chunk_alloc();
 	trace_percpu_create_chunk(base_addr);
 
@@ -2746,6 +2759,22 @@ void __init setup_per_cpu_areas(void)
 #endif	/* CONFIG_SMP */
 
 /*
+ * pcpu_nr_pages - calculate total number of populated backing pages
+ *
+ * This reflects the number of pages populated to back chunks.  Metadata is
+ * excluded in the number exposed in meminfo as the number of backing pages
+ * scales with the number of cpus and can quickly outweigh the memory used for
+ * metadata.  It also keeps this calculation nice and simple.
+ *
+ * RETURNS:
+ * Total number of populated backing pages in use by the allocator.
+ */
+unsigned long pcpu_nr_pages(void)
+{
+	return pcpu_nr_populated * pcpu_nr_units;
+}
+
+/*
  * Percpu allocator is initialized early during boot when neither slab or
  * workqueue is available.  Plug async management until everything is up
  * and running.