#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 {
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 */