From 2a1ddf27e8189e1d68336c55dd2f305b224ae8f1 Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Thu, 21 May 2015 12:16:40 +0200
Subject: [PATCH] pktgen: document ability to add same device to several
threads
The pktgen.txt documentation still claimed that adding same device to
multiple threads were not supported, but it have been since 2008 via
commit e6fce5b916cd7 ("pktgen: multiqueue etc.").
Document this and describe the naming scheme dev@X, as the procfile name
still need to be unique.
Fixes: e6fce5b916cd7 ("pktgen: multiqueue etc.")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
Documentation/networking/pktgen.txt | 77 +++++++++++++++++++----------
1 file changed, 50 insertions(+), 27 deletions(-)
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt
index d255434926d1..e7ae8b2939a8 100644
--- a/Documentation/networking/pktgen.txt
+++ b/Documentation/networking/pktgen.txt
@@ -50,16 +50,33 @@ For ixgbe use e.g. "30" resulting in approx 33K interrupts/sec (1/30*10^6):
# ethtool -C ethX rx-usecs 30
-Viewing threads
-===============
-/proc/net/pktgen/kpktgend_0
-Running:
-Stopped: eth1
-Result: OK: add_device=eth1
+Kernel threads
+==============
+Pktgen creates a thread for each CPU with affinity to that CPU.
+Which is controlled through procfile /proc/net/pktgen/kpktgend_X.
-Most important are the devices assigned to the thread. Note that a
-device can only belong to one thread.
+Example: /proc/net/pktgen/kpktgend_0
+ Running:
+ Stopped: eth4@0
+ Result: OK: add_device=eth4@0
+
+Most important are the devices assigned to the thread.
+
+The two basic thread commands are:
+ * add_device DEVICE@NAME -- adds a single device
+ * rem_device_all -- remove all associated devices
+
+When adding a device to a thread, a corrosponding procfile is created
+which is used for configuring this device. Thus, device names need to
+be unique.
+
+To support adding the same device to multiple threads, which is useful
+with multi queue NICs, a the device naming scheme is extended with "@":
+ device@something
+
+The part after "@" can be anything, but it is custom to use the thread
+number.
Viewing devices
===============
@@ -68,29 +85,32 @@ The Params section holds configured information. The Current section
holds running statistics. The Result is printed after a run or after
interruption. Example:
-/proc/net/pktgen/eth1
+/proc/net/pktgen/eth4@0
-Params: count 10000000 min_pkt_size: 60 max_pkt_size: 60
- frags: 0 delay: 0 clone_skb: 1000000 ifname: eth1
+ Params: count 100000 min_pkt_size: 60 max_pkt_size: 60
+ frags: 0 delay: 0 clone_skb: 64 ifname: eth4@0
flows: 0 flowlen: 0
- dst_min: 10.10.11.2 dst_max:
- src_min: src_max:
- src_mac: 00:00:00:00:00:00 dst_mac: 00:04:23:AC:FD:82
- udp_src_min: 9 udp_src_max: 9 udp_dst_min: 9 udp_dst_max: 9
- src_mac_count: 0 dst_mac_count: 0
- Flags:
-Current:
- pkts-sofar: 10000000 errors: 39664
- started: 1103053986245187us stopped: 1103053999346329us idle: 880401us
- seq_num: 10000011 cur_dst_mac_offset: 0 cur_src_mac_offset: 0
- cur_saddr: 0x10a0a0a cur_daddr: 0x20b0a0a
- cur_udp_dst: 9 cur_udp_src: 9
+ queue_map_min: 0 queue_map_max: 0
+ dst_min: 192.168.81.2 dst_max:
+ src_min: src_max:
+ src_mac: 90:e2:ba:0a:56:b4 dst_mac: 00:1b:21:3c:9d:f8
+ udp_src_min: 9 udp_src_max: 109 udp_dst_min: 9 udp_dst_max: 9
+ src_mac_count: 0 dst_mac_count: 0
+ Flags: UDPSRC_RND NO_TIMESTAMP QUEUE_MAP_CPU
+ Current:
+ pkts-sofar: 100000 errors: 0
+ started: 623913381008us stopped: 623913396439us idle: 25us
+ seq_num: 100001 cur_dst_mac_offset: 0 cur_src_mac_offset: 0
+ cur_saddr: 192.168.8.3 cur_daddr: 192.168.81.2
+ cur_udp_dst: 9 cur_udp_src: 42
+ cur_queue_map: 0
flows: 0
-Result: OK: 13101142(c12220741+d880401) usec, 10000000 (60byte,0frags)
- 763292pps 390Mb/sec (390805504bps) errors: 39664
+ Result: OK: 15430(c15405+d25) usec, 100000 (60byte,0frags)
+ 6480562pps 3110Mb/sec (3110669760bps) errors: 0
-Configuring threads and devices
-================================
+
+Configuring devices
+===================
This is done via the /proc interface, and most easily done via pgset
as defined in the sample scripts.
@@ -221,6 +241,9 @@ Note that when adding devices to a specific CPU it is a good idea to
also assign /proc/irq/XX/smp_affinity so that the TX interrupts are bound
to the same CPU. This reduces cache bouncing when freeing skbs.
+Plus using the device flag QUEUE_MAP_CPU, which maps the SKBs TX queue
+to the running threads CPU (directly from smp_processor_id()).
+
Enable IPsec
============
Default IPsec transformation with ESP encapsulation plus transport mode