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 <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Willem de Bruijn
2014-08-04 22:11:48 -04:00
committed by David S. Miller
parent 09c2d251b7
commit e7fd288538
6 changed files with 31 additions and 7 deletions

View File

@@ -132,6 +132,7 @@
#include <linux/hashtable.h>
#include <linux/vmalloc.h>
#include <linux/if_macvlan.h>
#include <linux/errqueue.h>
#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.
*/

View File

@@ -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)