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authorLi RongQing <lirongqing@baidu.com>2018-07-05 09:34:32 +0300
committerDavid S. Miller <davem@davemloft.net>2018-07-05 13:20:16 +0300
commit6312fe77751f57d4fa2b28abeef84c6a95c28136 (patch)
treebc8b1e2befbb98f1015785646f48e5f4172caebe /net/core/dev.c
parent6fcf9b1d4d6cd38202247de5c0ac7d85c4483abb (diff)
downloadlinux-6312fe77751f57d4fa2b28abeef84c6a95c28136.tar.xz
net: limit each hash list length to MAX_GRO_SKBS
After commit 07d78363dcff ("net: Convert NAPI gro list into a small hash table.")' there is 8 hash buckets, which allows more flows to be held for merging. but MAX_GRO_SKBS, the total held skb for merging, is 8 skb still, limit the hash table performance. keep MAX_GRO_SKBS as 8 skb, but limit each hash list length to 8 skb, not the total 8 skb Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/dev.c')
-rw-r--r--net/core/dev.c56
1 files changed, 23 insertions, 33 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 7e6a2f66db5c..89825c1eccdc 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -149,7 +149,6 @@
#include "net-sysfs.h"
-/* Instead of increasing this, you should create a hash table. */
#define MAX_GRO_SKBS 8
/* This should be increased if a protocol with a bigger head is added. */
@@ -5151,9 +5150,10 @@ out:
return netif_receive_skb_internal(skb);
}
-static void __napi_gro_flush_chain(struct napi_struct *napi, struct list_head *head,
+static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
bool flush_old)
{
+ struct list_head *head = &napi->gro_hash[index].list;
struct sk_buff *skb, *p;
list_for_each_entry_safe_reverse(skb, p, head, list) {
@@ -5162,22 +5162,20 @@ static void __napi_gro_flush_chain(struct napi_struct *napi, struct list_head *h
list_del_init(&skb->list);
napi_gro_complete(skb);
napi->gro_count--;
+ napi->gro_hash[index].count--;
}
}
-/* napi->gro_hash contains packets ordered by age.
+/* napi->gro_hash[].list contains packets ordered by age.
* youngest packets at the head of it.
* Complete skbs in reverse order to reduce latencies.
*/
void napi_gro_flush(struct napi_struct *napi, bool flush_old)
{
- int i;
-
- for (i = 0; i < GRO_HASH_BUCKETS; i++) {
- struct list_head *head = &napi->gro_hash[i];
+ u32 i;
- __napi_gro_flush_chain(napi, head, flush_old);
- }
+ for (i = 0; i < GRO_HASH_BUCKETS; i++)
+ __napi_gro_flush_chain(napi, i, flush_old);
}
EXPORT_SYMBOL(napi_gro_flush);
@@ -5189,7 +5187,7 @@ static struct list_head *gro_list_prepare(struct napi_struct *napi,
struct list_head *head;
struct sk_buff *p;
- head = &napi->gro_hash[hash & (GRO_HASH_BUCKETS - 1)];
+ head = &napi->gro_hash[hash & (GRO_HASH_BUCKETS - 1)].list;
list_for_each_entry(p, head, list) {
unsigned long diffs;
@@ -5257,27 +5255,13 @@ static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
}
}
-static void gro_flush_oldest(struct napi_struct *napi)
+static void gro_flush_oldest(struct list_head *head)
{
- struct sk_buff *oldest = NULL;
- unsigned long age = jiffies;
- int i;
-
- for (i = 0; i < GRO_HASH_BUCKETS; i++) {
- struct list_head *head = &napi->gro_hash[i];
- struct sk_buff *skb;
-
- if (list_empty(head))
- continue;
+ struct sk_buff *oldest;
- skb = list_last_entry(head, struct sk_buff, list);
- if (!oldest || time_before(NAPI_GRO_CB(skb)->age, age)) {
- oldest = skb;
- age = NAPI_GRO_CB(skb)->age;
- }
- }
+ oldest = list_last_entry(head, struct sk_buff, list);
- /* We are called with napi->gro_count >= MAX_GRO_SKBS, so this is
+ /* We are called with head length >= MAX_GRO_SKBS, so this is
* impossible.
*/
if (WARN_ON_ONCE(!oldest))
@@ -5292,6 +5276,7 @@ static void gro_flush_oldest(struct napi_struct *napi)
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
+ u32 hash = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
struct list_head *head = &offload_base;
struct packet_offload *ptype;
__be16 type = skb->protocol;
@@ -5358,6 +5343,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
list_del_init(&pp->list);
napi_gro_complete(pp);
napi->gro_count--;
+ napi->gro_hash[hash].count--;
}
if (same_flow)
@@ -5366,10 +5352,11 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
if (NAPI_GRO_CB(skb)->flush)
goto normal;
- if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
- gro_flush_oldest(napi);
+ if (unlikely(napi->gro_hash[hash].count >= MAX_GRO_SKBS)) {
+ gro_flush_oldest(gro_head);
} else {
napi->gro_count++;
+ napi->gro_hash[hash].count++;
}
NAPI_GRO_CB(skb)->count = 1;
NAPI_GRO_CB(skb)->age = jiffies;
@@ -6006,8 +5993,10 @@ void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
napi->timer.function = napi_watchdog;
napi->gro_count = 0;
- for (i = 0; i < GRO_HASH_BUCKETS; i++)
- INIT_LIST_HEAD(&napi->gro_hash[i]);
+ for (i = 0; i < GRO_HASH_BUCKETS; i++) {
+ INIT_LIST_HEAD(&napi->gro_hash[i].list);
+ napi->gro_hash[i].count = 0;
+ }
napi->skb = NULL;
napi->poll = poll;
if (weight > NAPI_POLL_WEIGHT)
@@ -6047,8 +6036,9 @@ static void flush_gro_hash(struct napi_struct *napi)
for (i = 0; i < GRO_HASH_BUCKETS; i++) {
struct sk_buff *skb, *n;
- list_for_each_entry_safe(skb, n, &napi->gro_hash[i], list)
+ list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
kfree_skb(skb);
+ napi->gro_hash[i].count = 0;
}
}