summaryrefslogtreecommitdiffstats
path: root/net/ipv4/udp.c
diff options
context:
space:
mode:
authorNandita Dukkipati <nanditad@google.com>2013-05-21 15:12:07 +0000
committerDavid S. Miller <davem@davemloft.net>2013-05-23 00:10:09 -0700
commit35f079ebbc860dcd1cca70890c9c8d59c1145525 (patch)
tree932fb1909f503a61997e6f691755f2f97fa6ee0b /net/ipv4/udp.c
parentd02cea0f4341b25cae044d2ec393049d60bff036 (diff)
tcp: bug fix in proportional rate reduction.
This patch is a fix for a bug triggering newly_acked_sacked < 0 in tcp_ack(.). The bug is triggered by sacked_out decreasing relative to prior_sacked, but packets_out remaining the same as pior_packets. This is because the snapshot of prior_packets is taken after tcp_sacktag_write_queue() while prior_sacked is captured before tcp_sacktag_write_queue(). The problem is: tcp_sacktag_write_queue (tcp_match_skb_to_sack() -> tcp_fragment) adjusts the pcount for packets_out and sacked_out (MSS change or other reason). As a result, this delta in pcount is reflected in (prior_sacked - sacked_out) but not in (prior_packets - packets_out). This patch does the following: 1) initializes prior_packets at the start of tcp_ack() so as to capture the delta in packets_out created by tcp_fragment. 2) introduces a new "previous_packets_out" variable that snapshots packets_out right before tcp_clean_rtx_queue, so pkts_acked can be correctly computed as before. 3) Computes pkts_acked using previous_packets_out, and computes newly_acked_sacked using prior_packets. Signed-off-by: Nandita Dukkipati <nanditad@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
0 files changed, 0 insertions, 0 deletions