diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-10-15 09:37:52 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-10-15 22:56:41 -0700 |
| commit | 5f6188a8003d080e3753b8f14f4a5a2325ae1ff6 (patch) | |
| tree | 17f35c12eeef92a69902b197a73c1123eaac9e63 /include/linux/tcp.h | |
| parent | 1a3aea2534f4f3083f29b2b047aa83a9d6c777a4 (diff) | |
tcp: do not change tcp_wstamp_ns in tcp_mstamp_refresh
In EDT design, I made the mistake of using tcp_wstamp_ns
to store the last tcp_clock_ns() sample and to store the
pacing virtual timer.
This causes major regressions at high speed flows.
Introduce tcp_clock_cache to store last tcp_clock_ns().
This is needed because some arches have slow high-resolution
kernel time service.
tcp_wstamp_ns is only updated when a packet is sent.
Note that we can remove tcp_mstamp in the future since
tcp_mstamp is essentially tcp_clock_cache/1000, so the
apparent socket size increase is temporary.
Fixes: 9799ccb0e984 ("tcp: add tcp_wstamp_ns socket field")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/tcp.h')
| -rw-r--r-- | include/linux/tcp.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 848f5b25e178..8ed77bb4ed86 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -249,6 +249,7 @@ struct tcp_sock { u32 tlp_high_seq; /* snd_nxt at the time of TLP retransmit. */ u64 tcp_wstamp_ns; /* departure time for next sent data packet */ + u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */ /* RTT measurement */ u64 tcp_mstamp; /* most recent packet received/sent */ |