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-rw-r--r--mm/percpu.c29
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.