diff options
author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-04-21 06:33:03 -0300 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-04-21 09:44:55 -0300 |
commit | 64131a87f2aae2ed9e05d8227c5b009ca6c50d98 (patch) | |
tree | fdea23fd59216120bf54a48c60ca24489a733f14 /Documentation/networking/pktgen.txt | |
parent | 676ee36be04985062522804c2de04f0764212be6 (diff) | |
parent | 2c33ce009ca2389dbf0535d0672214d09738e35e (diff) |
Merge branch 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux into v4l_for_linus
* 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux: (9717 commits)
media-bus: Fixup RGB444_1X12, RGB565_1X16, and YUV8_1X24 media bus format
hexdump: avoid warning in test function
fs: take i_mutex during prepare_binprm for set[ug]id executables
smp: Fix error case handling in smp_call_function_*()
iommu-common: Fix PARISC compile-time warnings
sparc: Make LDC use common iommu poll management functions
sparc: Make sparc64 use scalable lib/iommu-common.c functions
Break up monolithic iommu table/lock into finer graularity pools and lock
sparc: Revert generic IOMMU allocator.
tools/power turbostat: correct dumped pkg-cstate-limit value
tools/power turbostat: calculate TSC frequency from CPUID(0x15) on SKL
tools/power turbostat: correct DRAM RAPL units on recent Xeon processors
tools/power turbostat: Initial Skylake support
tools/power turbostat: Use $(CURDIR) instead of $(PWD) and add support for O= option in Makefile
tools/power turbostat: modprobe msr, if needed
tools/power turbostat: dump MSR_TURBO_RATIO_LIMIT2
tools/power turbostat: use new MSR_TURBO_RATIO_LIMIT names
Bluetooth: hidp: Fix regression with older userspace and flags validation
config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
perf/x86/intel/pt: Fix and clean up error handling in pt_event_add()
...
That solves several merge conflicts:
Documentation/DocBook/media/v4l/subdev-formats.xml
Documentation/devicetree/bindings/vendor-prefixes.txt
drivers/staging/media/mn88473/mn88473.c
include/linux/kconfig.h
include/uapi/linux/media-bus-format.h
The ones at subdev-formats.xml and media-bus-format.h are not trivial.
That's why we opted to merge from DRM.
Diffstat (limited to 'Documentation/networking/pktgen.txt')
-rw-r--r-- | Documentation/networking/pktgen.txt | 62 |
1 files changed, 32 insertions, 30 deletions
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt index 6915c6b27869..0344f1d45b37 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. |