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authorDave Airlie <airlied@redhat.com>2015-04-20 01:32:26 (GMT)
committerDave Airlie <airlied@redhat.com>2015-04-20 03:05:20 (GMT)
commit2c33ce009ca2389dbf0535d0672214d09738e35e (patch)
tree6186a6458c3c160385d794a23eaf07c786a9e61b /Documentation/networking/pktgen.txt
parentcec32a47010647e8b0603726ebb75b990a4057a4 (diff)
parent09d51602cf84a1264946711dd4ea0dddbac599a1 (diff)
downloadlinux-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.xz
Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards, due to API changes in the regulator tree. I've included the patch into the merge to fix the build. Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'Documentation/networking/pktgen.txt')
-rw-r--r--Documentation/networking/pktgen.txt62
1 files changed, 32 insertions, 30 deletions
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt
index 6915c6b..0344f1d 100644
--- a/Documentation/networking/pktgen.txt
+++ b/Documentation/networking/pktgen.txt
@@ -3,13 +3,11 @@
HOWTO for the linux packet generator
------------------------------------
-Date: 041221
-
-Enable CONFIG_NET_PKTGEN to compile and build pktgen.o either in kernel
-or as module. Module is preferred. insmod pktgen if needed. Once running
-pktgen creates a thread on each CPU where each thread has affinity to its CPU.
-Monitoring and controlling is done via /proc. Easiest to select a suitable
-a sample script and configure.
+Enable CONFIG_NET_PKTGEN to compile and build pktgen either in-kernel
+or as a module. A module is preferred; modprobe pktgen if needed. Once
+running, pktgen creates a thread for each CPU with affinity to that CPU.
+Monitoring and controlling is done via /proc. It is easiest to select a
+suitable sample script and configure that.
On a dual CPU:
@@ -27,7 +25,7 @@ For monitoring and control pktgen creates:
Tuning NIC for max performance
==============================
-The default NIC setting are (likely) not tuned for pktgen's artificial
+The default NIC settings are (likely) not tuned for pktgen's artificial
overload type of benchmarking, as this could hurt the normal use-case.
Specifically increasing the TX ring buffer in the NIC:
@@ -35,20 +33,20 @@ Specifically increasing the TX ring buffer in the NIC:
A larger TX ring can improve pktgen's performance, while it can hurt
in the general case, 1) because the TX ring buffer might get larger
-than the CPUs L1/L2 cache, 2) because it allow more queueing in the
+than the CPU's L1/L2 cache, 2) because it allows more queueing in the
NIC HW layer (which is bad for bufferbloat).
-One should be careful to conclude, that packets/descriptors in the HW
+One should hesitate to conclude that packets/descriptors in the HW
TX ring cause delay. Drivers usually delay cleaning up the
-ring-buffers (for various performance reasons), thus packets stalling
-the TX ring, might just be waiting for cleanup.
+ring-buffers for various performance reasons, and packets stalling
+the TX ring might just be waiting for cleanup.
-This cleanup issues is specifically the case, for the driver ixgbe
-(Intel 82599 chip). This driver (ixgbe) combine TX+RX ring cleanups,
+This cleanup issue is specifically the case for the driver ixgbe
+(Intel 82599 chip). This driver (ixgbe) combines TX+RX ring cleanups,
and the cleanup interval is affected by the ethtool --coalesce setting
of parameter "rx-usecs".
-For ixgbe use e.g "30" resulting in approx 33K interrupts/sec (1/30*10^6):
+For ixgbe use e.g. "30" resulting in approx 33K interrupts/sec (1/30*10^6):
# ethtool -C ethX rx-usecs 30
@@ -60,15 +58,16 @@ Running:
Stopped: eth1
Result: OK: max_before_softirq=10000
-Most important the devices assigned to thread. Note! A device can only belong
-to one thread.
+Most important are the devices assigned to the thread. Note that a
+device can only belong to one thread.
Viewing devices
===============
-Parm section holds configured info. Current hold running stats.
-Result is printed after run or after interruption. Example:
+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
@@ -93,7 +92,8 @@ Result: OK: 13101142(c12220741+d880401) usec, 10000000 (60byte,0frags)
Configuring threads and devices
================================
-This is done via the /proc interface easiest done via pgset in the scripts
+This is done via the /proc interface, and most easily done via pgset
+as defined in the sample scripts.
Examples:
@@ -192,10 +192,11 @@ Examples:
pgset "rate 300M" set rate to 300 Mb/s
pgset "ratep 1000000" set rate to 1Mpps
-Example scripts
-===============
+Sample scripts
+==============
-A collection of small tutorial scripts for pktgen is in examples dir.
+A collection of small tutorial scripts for pktgen is in the
+samples/pktgen directory:
pktgen.conf-1-1 # 1 CPU 1 dev
pktgen.conf-1-2 # 1 CPU 2 dev
@@ -206,25 +207,26 @@ pktgen.conf-1-1-ip6 # 1 CPU 1 dev ipv6
pktgen.conf-1-1-ip6-rdos # 1 CPU 1 dev ipv6 w. route DoS
pktgen.conf-1-1-flows # 1 CPU 1 dev multiple flows.
-Run in shell: ./pktgen.conf-X-Y It does all the setup including sending.
+Run in shell: ./pktgen.conf-X-Y
+This does all the setup including sending.
Interrupt affinity
===================
-Note when adding devices to a specific CPU there good idea to also assign
-/proc/irq/XX/smp_affinity so the TX-interrupts gets bound to the same CPU.
-as this reduces cache bouncing when freeing skb's.
+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.
Enable IPsec
============
-Default IPsec transformation with ESP encapsulation plus Transport mode
-could be enabled by simply setting:
+Default IPsec transformation with ESP encapsulation plus transport mode
+can be enabled by simply setting:
pgset "flag IPSEC"
pgset "flows 1"
To avoid breaking existing testbed scripts for using AH type and tunnel mode,
-user could use "pgset spi SPI_VALUE" to specify which formal of transformation
+you can use "pgset spi SPI_VALUE" to specify which transformation mode
to employ.