363ec39235
ktime_get() is too expensive on some cases, and we'd like to get
usec resolution timestamps in TCP stack.
This patch adds a light weight facility using a combination of
local_clock() and jiffies samples.
Instead of :
u64 t0, t1;
t0 = ktime_get();
// stuff
t1 = ktime_get();
delta_us = ktime_us_delta(t1, t0);
use :
struct skb_mstamp t0, t1;
skb_mstamp_get(&t0);
// stuff
skb_mstamp_get(&t1);
delta_us = skb_mstamp_us_delta(&t1, &t0);
Note : local_clock() might have a (bounded) drift between cpus.
Do not use this infra in place of ktime_get() without understanding the
issues.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Larry Brakmo <brakmo@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| video | ||
| xen | ||
| Kbuild | ||