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authorEric Dumazet <edumazet@google.com>2020-04-30 10:35:41 -0700
committerDavid S. Miller <davem@davemloft.net>2020-04-30 13:24:01 -0700
commit2b195850128f5bafde177b12489d9fa27962cc1e (patch)
treebbb5e20a0e2c8cb06bb28d316d89b7b821672cdc /include
parent3857c776240f0edef8639d7833626ab2ee7c7723 (diff)
tcp: add tp->dup_ack_counter
In commit 86de5921a3d5 ("tcp: defer SACK compression after DupThresh") I added a TCP_FASTRETRANS_THRESH bias to tp->compressed_ack in order to enable sack compression only after 3 dupacks. Since we plan to relax this rule for flows that involve stacks not requiring this old rule, this patch adds a distinct tp->dup_ack_counter. This means the TCP_FASTRETRANS_THRESH value is now used in a single location that a future patch can adjust: if (tp->dup_ack_counter < TCP_FASTRETRANS_THRESH) { tp->dup_ack_counter++; goto send_now; } This patch also introduces tcp_sack_compress_send_ack() helper to ease following patch comprehension. This patch refines LINUX_MIB_TCPACKCOMPRESSED to not count the acks that we had to send if the timer expires or tcp_sack_compress_send_ack() is sending an ack. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/tcp.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 421c99c12291..2c6f87e9f0cf 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -268,6 +268,7 @@ struct tcp_sock {
} rack;
u16 advmss; /* Advertised MSS */
u8 compressed_ack;
+ u8 dup_ack_counter;
u32 chrono_start; /* Start time in jiffies of a TCP chrono */
u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
u8 chrono_type:2, /* current chronograph type */