On Tue, 10 Nov 2009 22:53:17 -0800 Tom Herbert wrote:
quoted text > Third version of RPS.
>
> Signed-off-by: Tom Herbert <therbert@google.com>
> ---
> include/linux/interrupt.h | 1 +
> include/linux/netdevice.h | 18 ++++
> include/linux/skbuff.h | 2 +
> net/core/dev.c | 227 ++++++++++++++++++++++++++++++++++++++-------
> net/core/net-sysfs.c | 135 +++++++++++++++++++++++++++
> 5 files changed, 348 insertions(+), 35 deletions(-)
>
quoted text > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 0c68fbd..95feac7 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -396,6 +396,8 @@ struct sk_buff {
>
> __u16 vlan_tci;
>
> + __u32 rxhash;
> +
@rxhash needs to be added to the kernel-doc for struct sk_buff.
quoted text > sk_buff_data_t transport_header;
> sk_buff_data_t network_header;
> sk_buff_data_t mac_header;
quoted text > diff --git a/net/core/dev.c b/net/core/dev.c
> index 28b0b9e..735e7e3 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -1976,6 +1976,162 @@ int weight_p __read_mostly = 64; /*
> old backlog weight */
>
> DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
>
> +static u32 simple_hashrnd;
> +
> +/**
> + * get_rps_cpu is called from netif_receive_skb and returns the target
> + * CPU from the RPS map of the receiving NAPI instance for a given skb.
> + */
"/**" in kernel source code means "begin kernel-doc notation", but that
is not kernel-doc notation, so please make it be kernel-doc, or don't
use "/**" to begin comment blocks.
(in several functions here...)
quoted text > +static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb)
> +{
> + u32 addr1, addr2, ports;
> + struct ipv6hdr *ip6;
> + struct iphdr *ip;
> + u32 hash, ihl;
> + u8 ip_proto;
> + int cpu;
> + struct rps_map *map = NULL;
> +
> + if (dev->rps_num_maps) {
> + /*
> + * Locate the map corresponding to the NAPI queue that
> + * the packet was received on.
> + */
> + int index = skb_get_rx_queue(skb);
> + if (index < 0 || index >= dev->rps_num_maps)
> + index = 0;
> +
> + map = (struct rps_map *)
> + (dev->rps_maps + (RPS_MAP_SIZE * index));
> + if (!map->len)
> + map = NULL;
> + }
> +
> + if (!map)
> + return -1;
> +
> + hash = skb->rxhash;
> + if (hash)
> + goto got_hash; /* Skip hash computation on packet header */
> +
> + switch (skb->protocol) {
> + case __constant_htons(ETH_P_IP):
> + if (!pskb_may_pull(skb, sizeof(*ip)))
> + return -1;
> +
> + ip = (struct iphdr *) skb->data;
> + ip_proto = ip->protocol;
> + addr1 = ip->saddr;
> + addr2 = ip->daddr;
> + ihl = ip->ihl;
> + break;
> + case __constant_htons(ETH_P_IPV6):
> + if (!pskb_may_pull(skb, sizeof(*ip6)))
> + return -1;
> +
> + ip6 = (struct ipv6hdr *) skb->data;
> + ip_proto = ip6->nexthdr;
> + addr1 = ip6->saddr.s6_addr32[3];
> + addr2 = ip6->daddr.s6_addr32[3];
> + ihl = (40 >> 2);
> + break;
> + default:
> + return -1;
> + }
> + ports = 0;
> + switch (ip_proto) {
> + case IPPROTO_TCP:
> + case IPPROTO_UDP:
> + case IPPROTO_DCCP:
> + case IPPROTO_ESP:
> + case IPPROTO_AH:
> + case IPPROTO_SCTP:
> + case IPPROTO_UDPLITE:
> + if (pskb_may_pull(skb, (ihl * 4) + 4))
> + ports = *((u32 *) (skb->data + (ihl * 4)));
> + break;
> +
> + default:
> + break;
> + }
> +
> + hash = jhash_3words(addr1, addr2, ports, simple_hashrnd);
> +
> +got_hash:
> + cpu = map->map[((u64) hash * map->len) >> 32];
> +
> + return cpu_online(cpu) ? cpu : -1;
> +}
quoted text > +/**
> + * net_rps_action is called from NET_RPS_SOFTIRQ to do IPIs to schedule RX
> + * softirq on remote CPUs. Called in a separate softirq to allow for
> + * coalescing.
> + */
> +static void net_rps_action(struct softirq_action *h)
> +{
> + int cpu;
> +
> + local_irq_disable();
> +
> + for_each_cpu_mask_nr(cpu, __get_cpu_var(rps_remote_softirq_cpus)) {
> + struct softnet_data *queue = &per_cpu(softnet_data, cpu);
> + __smp_call_function_single(cpu, &queue->csd, 0);
> + }
> + cpus_clear(__get_cpu_var(rps_remote_softirq_cpus));
> +
> + local_irq_enable();
> +}
> +
> +/**
> + * enqueue_to_backlog is called to queue an skb to a per CPU backlog
> + * queue (may be a remote CPU queue).
> + */
> +static int enqueue_to_backlog(struct sk_buff *skb, int cpu)
> +{
quoted text > diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 753c420..ca250f6 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -18,6 +18,9 @@
> #include <linux/wireless.h>
> #include <net/wext.h>
>
> +#include <linux/string.h>
> +#include <linux/ctype.h>
> +
> #include "net-sysfs.h"
>
> #ifdef CONFIG_SYSFS
> @@ -249,6 +252,137 @@ static ssize_t store_tx_queue_len(struct device *dev,
> return netdev_store(dev, attr, buf, len, change_tx_queue_len);
> }
>
> +static char *
> +get_token(const char **cp, size_t *len)
> +{
nit: not kernel style.
---
~Randy
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