[v3,1/5] percpu: return number of released bytes from pcpu_free_area()
diff mbox series

Message ID 20200623184515.4132564-2-guro@fb.com
State New
Headers show
Series
  • mm: memcg accounting of percpu memory
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Commit Message

Roman Gushchin June 23, 2020, 6:45 p.m. UTC
To implement accounting of percpu memory we need the information about the
size of freed object.  Return it from pcpu_free_area().

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
---
 mm/percpu.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Comments

Shakeel Butt June 24, 2020, 12:58 a.m. UTC | #1
On Tue, Jun 23, 2020 at 11:47 AM Roman Gushchin <guro@fb.com> wrote:
>
> To implement accounting of percpu memory we need the information about the
> size of freed object.  Return it from pcpu_free_area().
>
> Signed-off-by: Roman Gushchin <guro@fb.com>
> Acked-by: Dennis Zhou <dennis@kernel.org>

Reviewed-by: Shakeel Butt <shakeelb@google.com>

Patch
diff mbox series

diff --git a/mm/percpu.c b/mm/percpu.c
index 696367b18222..aa36b78d45a6 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1211,11 +1211,14 @@  static int pcpu_alloc_area(struct pcpu_chunk *chunk, int alloc_bits,
  *
  * This function determines the size of an allocation to free using
  * the boundary bitmap and clears the allocation map.
+ *
+ * RETURNS:
+ * Number of freed bytes.
  */
-static void pcpu_free_area(struct pcpu_chunk *chunk, int off)
+static int pcpu_free_area(struct pcpu_chunk *chunk, int off)
 {
 	struct pcpu_block_md *chunk_md = &chunk->chunk_md;
-	int bit_off, bits, end, oslot;
+	int bit_off, bits, end, oslot, freed;
 
 	lockdep_assert_held(&pcpu_lock);
 	pcpu_stats_area_dealloc(chunk);
@@ -1230,8 +1233,10 @@  static void pcpu_free_area(struct pcpu_chunk *chunk, int off)
 	bits = end - bit_off;
 	bitmap_clear(chunk->alloc_map, bit_off, bits);
 
+	freed = bits * PCPU_MIN_ALLOC_SIZE;
+
 	/* update metadata */
-	chunk->free_bytes += bits * PCPU_MIN_ALLOC_SIZE;
+	chunk->free_bytes += freed;
 
 	/* update first free bit */
 	chunk_md->first_free = min(chunk_md->first_free, bit_off);
@@ -1239,6 +1244,8 @@  static void pcpu_free_area(struct pcpu_chunk *chunk, int off)
 	pcpu_block_update_hint_free(chunk, bit_off, bits);
 
 	pcpu_chunk_relocate(chunk, oslot);
+
+	return freed;
 }
 
 static void pcpu_init_md_block(struct pcpu_block_md *block, int nr_bits)