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| author | Coco Li <lixiaoyan@google.com> | 2022-01-05 02:48:38 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-01-06 12:27:05 +0000 |
| commit | eac1b93c14d645ef147b049ace0d5230df755548 (patch) | |
| tree | 1cbed37768a8189a8ff3cd4c8ca7e542e3595aca /net/core/rtnetlink.c | |
| parent | 007747a984ea5e895b7d8b056b24ebf431e1e71d (diff) | |
| download | lwn-eac1b93c14d645ef147b049ace0d5230df755548.tar.gz lwn-eac1b93c14d645ef147b049ace0d5230df755548.zip | |
gro: add ability to control gro max packet size
Eric Dumazet suggested to allow users to modify max GRO packet size.
We have seen GRO being disabled by users of appliances (such as
wifi access points) because of claimed bufferbloat issues,
or some work arounds in sch_cake, to split GRO/GSO packets.
Instead of disabling GRO completely, one can chose to limit
the maximum packet size of GRO packets, depending on their
latency constraints.
This patch adds a per device gro_max_size attribute
that can be changed with ip link command.
ip link set dev eth0 gro_max_size 16000
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/rtnetlink.c')
| -rw-r--r-- | net/core/rtnetlink.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index d6eba554b137..e476403231f0 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1026,6 +1026,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(4) /* IFLA_NUM_RX_QUEUES */ + nla_total_size(4) /* IFLA_GSO_MAX_SEGS */ + nla_total_size(4) /* IFLA_GSO_MAX_SIZE */ + + nla_total_size(4) /* IFLA_GRO_MAX_SIZE */ + nla_total_size(1) /* IFLA_OPERSTATE */ + nla_total_size(1) /* IFLA_LINKMODE */ + nla_total_size(4) /* IFLA_CARRIER_CHANGES */ @@ -1728,6 +1729,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, nla_put_u32(skb, IFLA_NUM_TX_QUEUES, dev->num_tx_queues) || nla_put_u32(skb, IFLA_GSO_MAX_SEGS, dev->gso_max_segs) || nla_put_u32(skb, IFLA_GSO_MAX_SIZE, dev->gso_max_size) || + nla_put_u32(skb, IFLA_GRO_MAX_SIZE, dev->gro_max_size) || #ifdef CONFIG_RPS nla_put_u32(skb, IFLA_NUM_RX_QUEUES, dev->num_rx_queues) || #endif @@ -1880,6 +1882,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_PROTO_DOWN_REASON] = { .type = NLA_NESTED }, [IFLA_NEW_IFINDEX] = NLA_POLICY_MIN(NLA_S32, 1), [IFLA_PARENT_DEV_NAME] = { .type = NLA_NUL_STRING }, + [IFLA_GRO_MAX_SIZE] = { .type = NLA_U32 }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -2299,6 +2302,14 @@ static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[], } } + if (tb[IFLA_GRO_MAX_SIZE]) { + u32 gro_max_size = nla_get_u32(tb[IFLA_GRO_MAX_SIZE]); + + if (gro_max_size > GRO_MAX_SIZE) { + NL_SET_ERR_MSG(extack, "too big gro_max_size"); + return -EINVAL; + } + } return 0; } @@ -2772,6 +2783,15 @@ static int do_setlink(const struct sk_buff *skb, } } + if (tb[IFLA_GRO_MAX_SIZE]) { + u32 gro_max_size = nla_get_u32(tb[IFLA_GRO_MAX_SIZE]); + + if (dev->gro_max_size ^ gro_max_size) { + netif_set_gro_max_size(dev, gro_max_size); + status |= DO_SETLINK_MODIFIED; + } + } + if (tb[IFLA_OPERSTATE]) set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE])); @@ -3222,6 +3242,8 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, netif_set_gso_max_size(dev, nla_get_u32(tb[IFLA_GSO_MAX_SIZE])); if (tb[IFLA_GSO_MAX_SEGS]) netif_set_gso_max_segs(dev, nla_get_u32(tb[IFLA_GSO_MAX_SEGS])); + if (tb[IFLA_GRO_MAX_SIZE]) + netif_set_gro_max_size(dev, nla_get_u32(tb[IFLA_GRO_MAX_SIZE])); return dev; } |