mirror of
				git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
				synced 2025-09-04 20:19:47 +08:00 
			
		
		
		
	 bb9b9f8802
			
		
	
	
		bb9b9f8802
		
	
	
	
	
		
			
			This patch writes 'node->ref = 1' only if node->ref is 0.
The number of lookups/s for a ~1M entries LRU map increased by
~30% (260097 to 343313).
Other writes on 'node->ref = 0' is not changed.  In those cases, the
same cache line has to be changed anyway.
First column: Size of the LRU hash
Second column: Number of lookups/s
Before:
> echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')"
1048577: 260097
After:
> echo "$((2**20+1)): $(./map_perf_test 1024 1 $((2**20+1)) 10000000 | awk '{print $3}')"
1048577: 343313
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
		
	
			
		
			
				
	
	
		
			86 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (c) 2016 Facebook
 | |
|  *
 | |
|  * This program is free software; you can redistribute it and/or
 | |
|  * modify it under the terms of version 2 of the GNU General Public
 | |
|  * License as published by the Free Software Foundation.
 | |
|  */
 | |
| #ifndef __BPF_LRU_LIST_H_
 | |
| #define __BPF_LRU_LIST_H_
 | |
| 
 | |
| #include <linux/list.h>
 | |
| #include <linux/spinlock_types.h>
 | |
| 
 | |
| #define NR_BPF_LRU_LIST_T	(3)
 | |
| #define NR_BPF_LRU_LIST_COUNT	(2)
 | |
| #define NR_BPF_LRU_LOCAL_LIST_T (2)
 | |
| #define BPF_LOCAL_LIST_T_OFFSET NR_BPF_LRU_LIST_T
 | |
| 
 | |
| enum bpf_lru_list_type {
 | |
| 	BPF_LRU_LIST_T_ACTIVE,
 | |
| 	BPF_LRU_LIST_T_INACTIVE,
 | |
| 	BPF_LRU_LIST_T_FREE,
 | |
| 	BPF_LRU_LOCAL_LIST_T_FREE,
 | |
| 	BPF_LRU_LOCAL_LIST_T_PENDING,
 | |
| };
 | |
| 
 | |
| struct bpf_lru_node {
 | |
| 	struct list_head list;
 | |
| 	u16 cpu;
 | |
| 	u8 type;
 | |
| 	u8 ref;
 | |
| };
 | |
| 
 | |
| struct bpf_lru_list {
 | |
| 	struct list_head lists[NR_BPF_LRU_LIST_T];
 | |
| 	unsigned int counts[NR_BPF_LRU_LIST_COUNT];
 | |
| 	/* The next inacitve list rotation starts from here */
 | |
| 	struct list_head *next_inactive_rotation;
 | |
| 
 | |
| 	raw_spinlock_t lock ____cacheline_aligned_in_smp;
 | |
| };
 | |
| 
 | |
| struct bpf_lru_locallist {
 | |
| 	struct list_head lists[NR_BPF_LRU_LOCAL_LIST_T];
 | |
| 	u16 next_steal;
 | |
| 	raw_spinlock_t lock;
 | |
| };
 | |
| 
 | |
| struct bpf_common_lru {
 | |
| 	struct bpf_lru_list lru_list;
 | |
| 	struct bpf_lru_locallist __percpu *local_list;
 | |
| };
 | |
| 
 | |
| typedef bool (*del_from_htab_func)(void *arg, struct bpf_lru_node *node);
 | |
| 
 | |
| struct bpf_lru {
 | |
| 	union {
 | |
| 		struct bpf_common_lru common_lru;
 | |
| 		struct bpf_lru_list __percpu *percpu_lru;
 | |
| 	};
 | |
| 	del_from_htab_func del_from_htab;
 | |
| 	void *del_arg;
 | |
| 	unsigned int hash_offset;
 | |
| 	unsigned int nr_scans;
 | |
| 	bool percpu;
 | |
| };
 | |
| 
 | |
| static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node)
 | |
| {
 | |
| 	/* ref is an approximation on access frequency.  It does not
 | |
| 	 * have to be very accurate.  Hence, no protection is used.
 | |
| 	 */
 | |
| 	if (!node->ref)
 | |
| 		node->ref = 1;
 | |
| }
 | |
| 
 | |
| int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,
 | |
| 		 del_from_htab_func del_from_htab, void *delete_arg);
 | |
| void bpf_lru_populate(struct bpf_lru *lru, void *buf, u32 node_offset,
 | |
| 		      u32 elem_size, u32 nr_elems);
 | |
| void bpf_lru_destroy(struct bpf_lru *lru);
 | |
| struct bpf_lru_node *bpf_lru_pop_free(struct bpf_lru *lru, u32 hash);
 | |
| void bpf_lru_push_free(struct bpf_lru *lru, struct bpf_lru_node *node);
 | |
| void bpf_lru_promote(struct bpf_lru *lru, struct bpf_lru_node *node);
 | |
| 
 | |
| #endif
 |