percpu: expose pcpu_nr_empty_pop_pages in pcpu_stats

Percpu memory holds a minimum threshold of pages that are populated in order to serve atomic percpu memory requests. This change makes it easier to verify that there are a minimum number of populated pages lying around. Signed-off-by: Dennis Zhou <[email protected]> Signed-off-by: Tejun Heo <[email protected]>
opendata26 · Jul 17, 2017 · 6b9b6f3 · 6b9b6f3
1 parent 0245916
commit 6b9b6f3
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diff --git a/mm/percpu-internal.h b/mm/percpu-internal.h
@@ -36,6 +36,7 @@ extern spinlock_t pcpu_lock;
 
 extern struct list_head *pcpu_slot;
 extern int pcpu_nr_slots;
+extern int pcpu_nr_empty_pop_pages;
 
 extern struct pcpu_chunk *pcpu_first_chunk;
 extern struct pcpu_chunk *pcpu_reserved_chunk;

diff --git a/mm/percpu-stats.c b/mm/percpu-stats.c
@@ -164,6 +164,7 @@ static int percpu_stats_show(struct seq_file *m, void *v)
 	PU(nr_max_chunks);
 	PU(min_alloc_size);
 	PU(max_alloc_size);
+	P("empty_pop_pages", pcpu_nr_empty_pop_pages);
 	seq_putc(m, '\n');
 
 #undef PU

diff --git a/mm/percpu.c b/mm/percpu.c
@@ -160,7 +160,7 @@ static LIST_HEAD(pcpu_map_extend_chunks);
  * The number of empty populated pages, protected by pcpu_lock.  The
  * reserved chunk doesn't contribute to the count.
  */
-static int pcpu_nr_empty_pop_pages;
+int pcpu_nr_empty_pop_pages;
 
 /*
  * Balance work is used to populate or destroy chunks asynchronously.  We