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- From 3e969c9695b45e1a052d43b367096ec99f2f0aac Mon Sep 17 00:00:00 2001
- From: John Crispin <[email protected]>
- Date: Thu, 10 Aug 2017 15:58:29 +0200
- Subject: [PATCH 48/57] net: core: add RPS balancer
- Signed-off-by: John Crispin <[email protected]>
- ---
- net/core/dev.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
- 1 file changed, 56 insertions(+), 1 deletion(-)
- --- a/net/core/dev.c
- +++ b/net/core/dev.c
- @@ -3628,6 +3628,58 @@ set_rps_cpu(struct net_device *dev, stru
- return rflow;
- }
-
- +#define RPS_TBL_SIZE_SHIFT 10
- +#define RPS_TBL_SIZE (1 << RPS_TBL_SIZE_SHIFT)
- +struct rps_table {
- + int core;
- + struct timer_list expire;
- +};
- +static struct rps_table rps_table[RPS_TBL_SIZE];
- +static int rps_table_last_core;
- +
- +static void rps_table_expire(unsigned long data)
- +{
- + struct rps_table *entry = (struct rps_table *) data;
- +
- + entry->core = -1;
- +}
- +
- +static int rps_table_core(struct rps_map *map)
- +{
- + int i;
- +
- + for (i = 0; i < map->len; i++) {
- + int cpu = map->cpus[(rps_table_last_core + i + 1) % map->len];
- + if (cpu_online(cpu)) {
- + rps_table_last_core = cpu;
- + return cpu;
- + }
- + }
- + return map->cpus[0];
- +}
- +
- +static int rps_table_lookup(struct rps_map *map, u32 hash)
- +{
- + int bucket = hash & 0x3ff;
- +
- + if (rps_table[bucket].core < 0)
- + rps_table[bucket].core = rps_table_core(map);
- + mod_timer(&rps_table[bucket].expire, jiffies + HZ);
- +
- + return rps_table[bucket].core;
- +}
- +
- +static void rps_table_init(void)
- +{
- + int i;
- +
- + for (i = 0; i < RPS_TBL_SIZE; i++) {
- + rps_table[i].core = -1;
- + setup_timer(&rps_table[i].expire, rps_table_expire,
- + (unsigned long) &rps_table[i]);
- + }
- +}
- +
- /*
- * get_rps_cpu is called from netif_receive_skb and returns the target
- * CPU from the RPS map of the receiving queue for a given skb.
- @@ -3717,7 +3769,7 @@ static int get_rps_cpu(struct net_device
- try_rps:
-
- if (map) {
- - tcpu = map->cpus[reciprocal_scale(hash, map->len)];
- + tcpu = rps_table_lookup(map, hash);
- if (cpu_online(tcpu)) {
- cpu = tcpu;
- goto done;
- @@ -8802,6 +8854,9 @@ static int __init net_dev_init(void)
- sd->backlog.weight = weight_p;
- }
-
- + if (IS_ENABLED(CONFIG_RPS))
- + rps_table_init();
- +
- dev_boot_phase = 0;
-
- /* The loopback device is special if any other network devices
|