X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=mm%2Fpercpu.c;h=a749d4d96e3ec72baa7da9c325230855243e0bfa;hb=f025571e96caa95ffc3c1792f762a584893de582;hp=0b6480979ac78147d4a3fe33d8aded2d5e9a1a75;hpb=84c3a0979c4c29711807747280dfecbb54b8af7c;p=linux.git

diff --git a/mm/percpu.c b/mm/percpu.c
index 0b6480979ac7..a749d4d96e3e 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -169,6 +169,14 @@ 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
@@ -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);
 
@@ -2745,6 +2758,22 @@ 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