From e7fd2885385157d46c85f282fc6d7d297db43e1f Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:48 -0400 Subject: [PATCH] net-timestamp: SCHED timestamp on entering packet scheduler Kernel transmit latency is often incurred in the packet scheduler. Introduce a new timestamp on transmission just before entering the scheduler. When data travels through multiple devices (bonding, tunneling, ...) each device will export an individual timestamp. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/skbuff.h | 11 +++++++++-- include/uapi/linux/errqueue.h | 1 + include/uapi/linux/net_tstamp.h | 3 ++- net/core/dev.c | 4 ++++ net/core/skbuff.c | 16 ++++++++++++---- net/socket.c | 3 +++ 6 files changed, 31 insertions(+), 7 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0e35b3af7317..50e1e9b3a5a5 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -229,7 +229,7 @@ enum { /* generate hardware time stamp */ SKBTX_HW_TSTAMP = 1 << 0, - /* generate software time stamp */ + /* generate software time stamp when queueing packet to NIC */ SKBTX_SW_TSTAMP = 1 << 1, /* device driver is going to provide hardware time stamp */ @@ -247,9 +247,12 @@ enum { * all frags to avoid possible bad checksum */ SKBTX_SHARED_FRAG = 1 << 5, + + /* generate software time stamp when entering packet scheduling */ + SKBTX_SCHED_TSTAMP = 1 << 6, }; -#define SKBTX_ANY_SW_TSTAMP SKBTX_SW_TSTAMP +#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* @@ -2695,6 +2698,10 @@ static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) void skb_complete_tx_timestamp(struct sk_buff *skb, struct skb_shared_hwtstamps *hwtstamps); +void __skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, int tstype); + /** * skb_tstamp_tx - queue clone of skb with send time stamps * @orig_skb: the original outgoing packet diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index accee72cae7c..17437cf297b7 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -39,6 +39,7 @@ struct scm_timestamping { */ enum { SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ + SCM_TSTAMP_SCHED, /* data entered the packet scheduler */ }; #endif /* _UAPI_LINUX_ERRQUEUE_H */ diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index 1e861d2e1a31..60733845fcdd 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -21,8 +21,9 @@ enum { SOF_TIMESTAMPING_SYS_HARDWARE = (1<<5), SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6), SOF_TIMESTAMPING_OPT_ID = (1<<7), + SOF_TIMESTAMPING_TX_SCHED = (1<<8), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_SCHED, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/core/dev.c b/net/core/dev.c index b370230fe1d3..1c15b189c52b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -132,6 +132,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -2876,6 +2877,9 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) skb_reset_mac_header(skb); + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP)) + __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED); + /* Disable soft irqs for various locks below. Also * stops preemption for RCU. */ diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0df4f1d14c5a..9705c0732aab 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3490,10 +3490,10 @@ int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(sock_queue_err_skb); -void skb_tstamp_tx(struct sk_buff *orig_skb, - struct skb_shared_hwtstamps *hwtstamps) +void __skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, int tstype) { - struct sock *sk = orig_skb->sk; struct sock_exterr_skb *serr; struct sk_buff *skb; int err; @@ -3521,7 +3521,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, memset(serr, 0, sizeof(*serr)); serr->ee.ee_errno = ENOMSG; serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; - serr->ee.ee_info = SCM_TSTAMP_SND; + serr->ee.ee_info = tstype; if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) serr->ee.ee_data = skb_shinfo(skb)->tskey; @@ -3530,6 +3530,14 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, if (err) kfree_skb(skb); } +EXPORT_SYMBOL_GPL(__skb_tstamp_tx); + +void skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps) +{ + return __skb_tstamp_tx(orig_skb, hwtstamps, orig_skb->sk, + SCM_TSTAMP_SND); +} EXPORT_SYMBOL_GPL(skb_tstamp_tx); void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) diff --git a/net/socket.c b/net/socket.c index 255d9b802723..3a2778d71631 100644 --- a/net/socket.c +++ b/net/socket.c @@ -617,6 +617,9 @@ void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags) *tx_flags |= SKBTX_HW_TSTAMP; if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SOFTWARE) *tx_flags |= SKBTX_SW_TSTAMP; + if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED) + *tx_flags |= SKBTX_SCHED_TSTAMP; + if (sock_flag(sk, SOCK_WIFI_STATUS)) *tx_flags |= SKBTX_WIFI_STATUS; } -- GitLab