diff options
| author | Eric Dumazet <dada1@cosmosbay.com> | 2007-04-19 16:16:32 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-25 22:23:34 -0700 |
| commit | b7aa0bf70c4afb9e38be25f5c0922498d0f8684c (patch) | |
| tree | 4bc9d61031f4eb40d73887d6bde09e7d6bf2b259 /include/net/sock.h | |
| parent | 3927f2e8f9afa3424bb51ca81f7abac01ffd0005 (diff) | |
[NET]: convert network timestamps to ktime_t
We currently use a special structure (struct skb_timeval) and plain
'struct timeval' to store packet timestamps in sk_buffs and struct
sock.
This has some drawbacks :
- Fixed resolution of micro second.
- Waste of space on 64bit platforms where sizeof(struct timeval)=16
I suggest using ktime_t that is a nice abstraction of high resolution
time services, currently capable of nanosecond resolution.
As sizeof(ktime_t) is 8 bytes, using ktime_t in 'struct sock' permits
a 8 byte shrink of this structure on 64bit architectures. Some other
structures also benefit from this size reduction (struct ipq in
ipv4/ip_fragment.c, struct frag_queue in ipv6/reassembly.c, ...)
Once this ktime infrastructure adopted, we can more easily provide
nanosecond resolution on top of it. (ioctl SIOCGSTAMPNS and/or
SO_TIMESTAMPNS/SCM_TIMESTAMPNS)
Note : this patch includes a bug correction in
compat_sock_get_timestamp() where a "err = 0;" was missing (so this
syscall returned -ENOENT instead of 0)
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
CC: Stephen Hemminger <shemminger@linux-foundation.org>
CC: John find <linux.kernel@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index a3366c3c837..9583639090d 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -244,7 +244,7 @@ struct sock { struct sk_filter *sk_filter; void *sk_protinfo; struct timer_list sk_timer; - struct timeval sk_stamp; + ktime_t sk_stamp; struct socket *sk_socket; void *sk_user_data; struct page *sk_sndmsg_page; @@ -1307,19 +1307,19 @@ static inline int sock_intr_errno(long timeo) static __inline__ void sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) { - struct timeval stamp; + ktime_t kt = skb->tstamp; - skb_get_timestamp(skb, &stamp); if (sock_flag(sk, SOCK_RCVTSTAMP)) { + struct timeval tv; /* Race occurred between timestamp enabling and packet receiving. Fill in the current time for now. */ - if (stamp.tv_sec == 0) - do_gettimeofday(&stamp); - skb_set_timestamp(skb, &stamp); - put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval), - &stamp); + if (kt.tv64 == 0) + kt = ktime_get_real(); + skb->tstamp = kt; + tv = ktime_to_timeval(kt); + put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(tv), &tv); } else - sk->sk_stamp = stamp; + sk->sk_stamp = kt; } /** |