diff options
| author | Hans Westgaard Ry <hans.westgaard.ry@oracle.com> | 2016-02-03 09:26:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-08 09:43:05 +0100 |
| commit | df93393787a3fc3b994c5061a890b0250bae0fbc (patch) | |
| tree | 8a971649ccb5573fcb38204db242baa00b374cfe | |
| parent | 1115c5f029831fd3a9f447094069bb01802418a1 (diff) | |
| download | linux-linaro-stable-df93393787a3fc3b994c5061a890b0250bae0fbc.tar.gz | |
net:Add sysctl_max_skb_frags
commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 upstream.
Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.
Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | include/linux/skbuff.h | 1 | ||||
| -rw-r--r-- | net/core/skbuff.c | 2 | ||||
| -rw-r--r-- | net/core/sysctl_net_core.c | 10 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
4 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 3b57c6712495..2ff757f2d3a3 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -188,6 +188,7 @@ struct sk_buff; #else #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) #endif +extern int sysctl_max_skb_frags; typedef struct skb_frag_struct skb_frag_t; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b2921c0d5608..97549212e9e3 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -77,6 +77,8 @@ struct kmem_cache *skbuff_head_cache __read_mostly; static struct kmem_cache *skbuff_fclone_cache __read_mostly; +int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; +EXPORT_SYMBOL(sysctl_max_skb_frags); /** * skb_panic - private function for out-of-line support diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index e731c96eac4b..cd386d2fd039 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -27,6 +27,7 @@ static int one = 1; static int ushort_max = USHRT_MAX; static int min_sndbuf = SOCK_MIN_SNDBUF; static int min_rcvbuf = SOCK_MIN_RCVBUF; +static int max_skb_frags = MAX_SKB_FRAGS; #ifdef CONFIG_RPS static int rps_sock_flow_sysctl(struct ctl_table *table, int write, @@ -363,6 +364,15 @@ static struct ctl_table net_core_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "max_skb_frags", + .data = &sysctl_max_skb_frags, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, + .extra2 = &max_skb_frags, + }, { } }; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 32b25cc96fff..a21c47289765 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -939,7 +939,7 @@ new_segment: i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= MAX_SKB_FRAGS) { + if (!can_coalesce && i >= sysctl_max_skb_frags) { tcp_mark_push(tp, skb); goto new_segment; } @@ -1225,7 +1225,7 @@ new_segment: if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i == MAX_SKB_FRAGS || !sg) { + if (i == sysctl_max_skb_frags || !sg) { tcp_mark_push(tp, skb); goto new_segment; } |