Add one commit that fixes network regression

2 files changed, 139 insertions, 0 deletions

diff --git a/patches/net-do-not-enable-tx-nocache-copy-by-default.patch b/patches/net-do-not-enable-tx-nocache-copy-by-default.patch
new file mode 100644
index 0000000..cb7341b
--- /dev/null
+++ b/patches/net-do-not-enable-tx-nocache-copy-by-default.patch
@@ -0,0 +1,138 @@
+From cdb3f4a31b64c3a1c6eef40bc01ebc9594c58a8c Mon Sep 17 00:00:00 2001
+From: Benjamin Poirier <bpoirier@suse.de>
+Date: Tue, 7 Jan 2014 10:11:10 -0500
+Subject: net: Do not enable tx-nocache-copy by default
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+commit cdb3f4a31b64c3a1c6eef40bc01ebc9594c58a8c upstream.
+
+There are many cases where this feature does not improve performance or even
+reduces it.
+
+For example, here are the results from tests that I've run using 3.12.6 on one
+Intel Xeon W3565 and one i7 920 connected by ixgbe adapters. The results are
+from the Xeon, but they're similar on the i7. All numbers report the
+mean±stddev over 10 runs of 10s.
+
+1) latency tests similar to what is described in "c6e1a0d net: Allow no-cache
+copy from user on transmit"
+There is no statistically significant difference between tx-nocache-copy
+on/off.
+nic irqs spread out (one queue per cpu)
+
+200x netperf -r 1400,1
+tx-nocache-copy off
+        692000±1000 tps
+        50/90/95/99% latency (us): 275±2/643.8±0.4/799±1/2474.4±0.3
+tx-nocache-copy on
+        693000±1000 tps
+        50/90/95/99% latency (us): 274±1/644.1±0.7/800±2/2474.5±0.7
+
+200x netperf -r 14000,14000
+tx-nocache-copy off
+        86450±80 tps
+        50/90/95/99% latency (us): 334.37±0.02/838±1/2100±20/3990±40
+tx-nocache-copy on
+        86110±60 tps
+        50/90/95/99% latency (us): 334.28±0.01/837±2/2110±20/3990±20
+
+2) single stream throughput tests
+tx-nocache-copy leads to higher service demand
+
+                        throughput  cpu0        cpu1        demand
+                        (Gb/s)      (Gcycle)    (Gcycle)    (cycle/B)
+
+nic irqs and netperf on cpu0 (1x netperf -T0,0 -t omni -- -d send)
+
+tx-nocache-copy off     9402±5      9.4±0.2                 0.80±0.01
+tx-nocache-copy on      9403±3      9.85±0.04               0.838±0.004
+
+nic irqs on cpu0, netperf on cpu1 (1x netperf -T1,1 -t omni -- -d send)
+
+tx-nocache-copy off     9401±5      5.83±0.03   5.0±0.1     0.923±0.007
+tx-nocache-copy on      9404±2      5.74±0.03   5.523±0.009 0.958±0.002
+
+As a second example, here are some results from Eric Dumazet with latest
+net-next.
+tx-nocache-copy also leads to higher service demand
+
+(cpu is Intel(R) Xeon(R) CPU X5660  @ 2.80GHz)
+
+lpq83:~# ./ethtool -K eth0 tx-nocache-copy on
+lpq83:~# perf stat ./netperf -H lpq84 -c
+MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to lpq84.prod.google.com () port 0 AF_INET
+Recv   Send    Send                          Utilization       Service Demand
+Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
+Size   Size    Size     Time     Throughput  local    remote   local   remote
+bytes  bytes   bytes    secs.    10^6bits/s  % S      % U      us/KB   us/KB
+
+ 87380  16384  16384    10.00      9407.44   2.50     -1.00    0.522   -1.000
+
+ Performance counter stats for './netperf -H lpq84 -c':
+
+       4282.648396 task-clock                #    0.423 CPUs utilized
+             9,348 context-switches          #    0.002 M/sec
+                88 CPU-migrations            #    0.021 K/sec
+               355 page-faults               #    0.083 K/sec
+    11,812,797,651 cycles                    #    2.758 GHz                     [82.79%]
+     9,020,522,817 stalled-cycles-frontend   #   76.36% frontend cycles idle    [82.54%]
+     4,579,889,681 stalled-cycles-backend    #   38.77% backend  cycles idle    [67.33%]
+     6,053,172,792 instructions              #    0.51  insns per cycle
+                                             #    1.49  stalled cycles per insn [83.64%]
+       597,275,583 branches                  #  139.464 M/sec                   [83.70%]
+         8,960,541 branch-misses             #    1.50% of all branches         [83.65%]
+
+      10.128990264 seconds time elapsed
+
+lpq83:~# ./ethtool -K eth0 tx-nocache-copy off
+lpq83:~# perf stat ./netperf -H lpq84 -c
+MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to lpq84.prod.google.com () port 0 AF_INET
+Recv   Send    Send                          Utilization       Service Demand
+Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
+Size   Size    Size     Time     Throughput  local    remote   local   remote
+bytes  bytes   bytes    secs.    10^6bits/s  % S      % U      us/KB   us/KB
+
+ 87380  16384  16384    10.00      9412.45   2.15     -1.00    0.449   -1.000
+
+ Performance counter stats for './netperf -H lpq84 -c':
+
+       2847.375441 task-clock                #    0.281 CPUs utilized
+            11,632 context-switches          #    0.004 M/sec
+                49 CPU-migrations            #    0.017 K/sec
+               354 page-faults               #    0.124 K/sec
+     7,646,889,749 cycles                    #    2.686 GHz                     [83.34%]
+     6,115,050,032 stalled-cycles-frontend   #   79.97% frontend cycles idle    [83.31%]
+     1,726,460,071 stalled-cycles-backend    #   22.58% backend  cycles idle    [66.55%]
+     2,079,702,453 instructions              #    0.27  insns per cycle
+                                             #    2.94  stalled cycles per insn [83.22%]
+       363,773,213 branches                  #  127.757 M/sec                   [83.29%]
+         4,242,732 branch-misses             #    1.17% of all branches         [83.51%]
+
+      10.128449949 seconds time elapsed
+
+CC: Tom Herbert <therbert@google.com>
+Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Zefan Li <lizefan@huawei.com>
+---
+ net/core/dev.c |    5 -----
+ 1 file changed, 5 deletions(-)
+
+--- a/net/core/dev.c
++++ b/net/core/dev.c
+@@ -5546,13 +5546,8 @@ int register_netdevice(struct net_device
+ 	dev->features |= NETIF_F_SOFT_FEATURES;
+ 	dev->wanted_features = dev->features & dev->hw_features;
+ 
+-	/* Turn on no cache copy if HW is doing checksum */
+ 	if (!(dev->flags & IFF_LOOPBACK)) {
+ 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
+-		if (dev->features & NETIF_F_ALL_CSUM) {
+-			dev->wanted_features |= NETIF_F_NOCACHE_COPY;
+-			dev->features |= NETIF_F_NOCACHE_COPY;
+-		}
+ 	}
+ 
+ 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
diff --git a/patches/series b/patches/series
index ad92e7e..e030510 100644
--- a/patches/series
+++ b/patches/series
@@ -87,3 +87,4 @@ ipv4-avoid-parallel-route-cache-gc-executions.patch
 ipv4-disable-bh-while-doing-route-gc.patch
 rtl8192ce-Fix-null-dereference-in-watchdog.patch
 ipv6-reuse-ip6_frag_id-from-ip6_ufo_append_data.patch
+net-do-not-enable-tx-nocache-copy-by-default.patch