diff options
Diffstat (limited to 'target/linux/generic/patches-3.10/010-tsq_queueing_minimum.patch')
| -rw-r--r-- | target/linux/generic/patches-3.10/010-tsq_queueing_minimum.patch | 80 |
1 files changed, 0 insertions, 80 deletions
diff --git a/target/linux/generic/patches-3.10/010-tsq_queueing_minimum.patch b/target/linux/generic/patches-3.10/010-tsq_queueing_minimum.patch deleted file mode 100644 index 2d2dafc..0000000 --- a/target/linux/generic/patches-3.10/010-tsq_queueing_minimum.patch +++ /dev/null @@ -1,80 +0,0 @@ -From 98e09386c0ef4dfd48af7ba60ff908f0d525cdee Mon Sep 17 00:00:00 2001 -From: Eric Dumazet <edumazet@google.com> -Date: Wed, 13 Nov 2013 14:32:54 +0000 -Subject: tcp: tsq: restore minimal amount of queueing - -After commit c9eeec26e32e ("tcp: TSQ can use a dynamic limit"), several -users reported throughput regressions, notably on mvneta and wifi -adapters. - -802.11 AMPDU requires a fair amount of queueing to be effective. - -This patch partially reverts the change done in tcp_write_xmit() -so that the minimal amount is sysctl_tcp_limit_output_bytes. - -It also remove the use of this sysctl while building skb stored -in write queue, as TSO autosizing does the right thing anyway. - -Users with well behaving NICS and correct qdisc (like sch_fq), -can then lower the default sysctl_tcp_limit_output_bytes value from -128KB to 8KB. - -This new usage of sysctl_tcp_limit_output_bytes permits each driver -authors to check how their driver performs when/if the value is set -to a minimum of 4KB. - -Normally, line rate for a single TCP flow should be possible, -but some drivers rely on timers to perform TX completion and -too long TX completion delays prevent reaching full throughput. - -Fixes: c9eeec26e32e ("tcp: TSQ can use a dynamic limit") -Signed-off-by: Eric Dumazet <edumazet@google.com> -Reported-by: Sujith Manoharan <sujith@msujith.org> -Reported-by: Arnaud Ebalard <arno@natisbad.org> -Tested-by: Sujith Manoharan <sujith@msujith.org> -Cc: Felix Fietkau <nbd@openwrt.org> -Signed-off-by: David S. Miller <davem@davemloft.net> ---- ---- a/Documentation/networking/ip-sysctl.txt -+++ b/Documentation/networking/ip-sysctl.txt -@@ -571,9 +571,6 @@ tcp_limit_output_bytes - INTEGER - typical pfifo_fast qdiscs. - tcp_limit_output_bytes limits the number of bytes on qdisc - or device to reduce artificial RTT/cwnd and reduce bufferbloat. -- Note: For GSO/TSO enabled flows, we try to have at least two -- packets in flight. Reducing tcp_limit_output_bytes might also -- reduce the size of individual GSO packet (64KB being the max) - Default: 131072 - - tcp_challenge_ack_limit - INTEGER ---- a/net/ipv4/tcp.c -+++ b/net/ipv4/tcp.c -@@ -807,12 +807,6 @@ static unsigned int tcp_xmit_size_goal(s - xmit_size_goal = min_t(u32, gso_size, - sk->sk_gso_max_size - 1 - hlen); - -- /* TSQ : try to have at least two segments in flight -- * (one in NIC TX ring, another in Qdisc) -- */ -- xmit_size_goal = min_t(u32, xmit_size_goal, -- sysctl_tcp_limit_output_bytes >> 1); -- - xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal); - - /* We try hard to avoid divides here */ ---- a/net/ipv4/tcp_output.c -+++ b/net/ipv4/tcp_output.c -@@ -1866,8 +1866,12 @@ static bool tcp_write_xmit(struct sock * - * - better RTT estimation and ACK scheduling - * - faster recovery - * - high rates -+ * Alas, some drivers / subsystems require a fair amount -+ * of queued bytes to ensure line rate. -+ * One example is wifi aggregation (802.11 AMPDU) - */ -- limit = max(skb->truesize, sk->sk_pacing_rate >> 10); -+ limit = max_t(unsigned int, sysctl_tcp_limit_output_bytes, -+ sk->sk_pacing_rate >> 10); - - if (atomic_read(&sk->sk_wmem_alloc) > limit) { - set_bit(TSQ_THROTTLED, &tp->tsq_flags); |