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| 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 /net/core/dev.c | |
| parent | 3927f2e8f9afa3424bb51ca81f7abac01ffd0005 (diff) | |
| download | linux-b7aa0bf70c4afb9e38be25f5c0922498d0f8684c.tar.bz2 | |
[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 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 19 |
1 files changed, 4 insertions, 15 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 4dc93cc4d5b7..582db646cc54 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1031,23 +1031,12 @@ void net_disable_timestamp(void) atomic_dec(&netstamp_needed); } -void __net_timestamp(struct sk_buff *skb) -{ - struct timeval tv; - - do_gettimeofday(&tv); - skb_set_timestamp(skb, &tv); -} -EXPORT_SYMBOL(__net_timestamp); - static inline void net_timestamp(struct sk_buff *skb) { if (atomic_read(&netstamp_needed)) __net_timestamp(skb); - else { - skb->tstamp.off_sec = 0; - skb->tstamp.off_usec = 0; - } + else + skb->tstamp.tv64 = 0; } /* @@ -1577,7 +1566,7 @@ int netif_rx(struct sk_buff *skb) if (netpoll_rx(skb)) return NET_RX_DROP; - if (!skb->tstamp.off_sec) + if (!skb->tstamp.tv64) net_timestamp(skb); /* @@ -1769,7 +1758,7 @@ int netif_receive_skb(struct sk_buff *skb) if (skb->dev->poll && netpoll_rx(skb)) return NET_RX_DROP; - if (!skb->tstamp.off_sec) + if (!skb->tstamp.tv64) net_timestamp(skb); if (!skb->iif) |