1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 8a3c4a1caa14..24db9142e93b 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -199,6 +199,16 @@ struct swap_cluster_info {
 #define CLUSTER_FLAG_NEXT_NULL 2 /* This cluster has no next cluster */
 
 /*
+ * We assign a cluster to each CPU, so each CPU can allocate swap entry from
+ * its own cluster and swapout sequentially. The purpose is to optimize swapout
+ * throughput.
+ */
+struct percpu_cluster {
+        struct swap_cluster_info index; /* Current cluster index */
+        unsigned int next; /* Likely next allocation offset */
+};
+
+/*
  * The in-memory structure used to track swap areas.
  */
 struct swap_info_struct {
@@ -217,6 +227,7 @@ struct swap_info_struct {
         unsigned int inuse_pages;       /* number of those currently in use */
         unsigned int cluster_next;      /* likely index for next allocation */
         unsigned int cluster_nr;        /* countdown to next cluster search */
+        struct percpu_cluster __percpu *percpu_cluster; /* per cpu's swap location */
         struct swap_extent *curr_swap_extent;
         struct swap_extent first_swap_extent;
         struct block_device *bdev;      /* swap device or bdev of swap file */