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| author |   Ingo Molnar <mingo@elte.hu> | 2009-12-14 09:16:49 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-12-14 09:16:49 +0100 |
| commit | cc0104e877fff32865a67b256d3a9ce52ff15790 (patch) | |
| tree | 18779442274e81607822ecb0905c55ac4ce6a163 /net/ipv4/tcp_timer.c | |
| parent | ksym_tracer: Fix bad cast (diff) | |
| parent | Merge branch 'ixp4xx' of git://git.kernel.org/pub/scm/linux/kernel/git/chris/linux-2.6 (diff) | |
| download | linux-dev-cc0104e877fff32865a67b256d3a9ce52ff15790.tar.xz linux-dev-cc0104e877fff32865a67b256d3a9ce52ff15790.zip | |
Merge branch 'linus' into tracing/urgent
Conflicts:
kernel/trace/trace_kprobe.c
Merge reason: resolve the conflict.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'net/ipv4/tcp_timer.c')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 8353a538cd4c..8816a20c2597 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -132,6 +132,35 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) } } +/* This function calculates a "timeout" which is equivalent to the timeout of a + * TCP connection after "boundary" unsucessful, exponentially backed-off + * retransmissions with an initial RTO of TCP_RTO_MIN. + */ +static bool retransmits_timed_out(struct sock *sk, + unsigned int boundary) +{ + unsigned int timeout, linear_backoff_thresh; + unsigned int start_ts; + + if (!inet_csk(sk)->icsk_retransmits) + return false; + + if (unlikely(!tcp_sk(sk)->retrans_stamp)) + start_ts = TCP_SKB_CB(tcp_write_queue_head(sk))->when; + else + start_ts = tcp_sk(sk)->retrans_stamp; + + linear_backoff_thresh = ilog2(TCP_RTO_MAX/TCP_RTO_MIN); + + if (boundary <= linear_backoff_thresh) + timeout = ((2 << boundary) - 1) * TCP_RTO_MIN; + else + timeout = ((2 << linear_backoff_thresh) - 1) * TCP_RTO_MIN + + (boundary - linear_backoff_thresh) * TCP_RTO_MAX; + + return (tcp_time_stamp - start_ts) >= timeout; +} + /* A write timeout has occurred. Process the after effects. */ static int tcp_write_timeout(struct sock *sk) { |