Using pktgen I'm seeing the ixgbe driver "push-back", due TX ring
running full.  Thus, the TX ring is artificially limiting pktgen.
(Diagnose via "ethtool -S", look for "tx_restart_queue" or "tx_busy"
counters.)

Using ixgbe, the real reason behind the TX ring running full, is due
to TX ring not being cleaned up fast enough. The ixgbe driver combines
TX+RX ring cleanups, and the cleanup interval is affected by the
ethtool --coalesce setting of parameter "rx-usecs".

Do not increase the default NIC TX ring buffer or default cleanup
interval.  Instead simply document that pktgen needs special NIC
tuning for maximum packet per sec performance.

Performance results with pktgen with clone_skb=100000.
TX ring size 512 (default), adjusting "rx-usecs":
 (Single CPU performance, E5-2630, ixgbe)
 - 3935002 pps - rx-usecs:  1 (irqs:  9346)
 - 5132350 pps - rx-usecs: 10 (irqs: 99157)
 - 5375111 pps - rx-usecs: 20 (irqs: 50154)
 - 5454050 pps - rx-usecs: 30 (irqs: 33872)
 - 5496320 pps - rx-usecs: 40 (irqs: 26197)
 - 5502510 pps - rx-usecs: 50 (irqs: 21527)

TX ring size adjusting (ethtool -G), "rx-usecs==1" (default):
 - 3935002 pps - tx-size:  512
 - 5354401 pps - tx-size:  768
 - 5356847 pps - tx-size: 1024
 - 5327595 pps - tx-size: 1536
 - 5356779 pps - tx-size: 2048
 - 5353438 pps - tx-size: 4096

Notice after commit 6f25cd47 (pktgen: fix xmit test for BQL enabled
devices) pktgen uses netif_xmit_frozen_or_drv_stopped() and ignores
the BQL "stack" pause (QUEUE_STATE_STACK_XOFF) flag.  This allow us to put
more pressure on the TX ring buffers.

It is the ixgbe_maybe_stop_tx() call that stops the transmits, and
pktgen respecting this in the call to netif_xmit_frozen_or_drv_stopped(txq).
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The documentation misses a few of the supported flags. Fix this. Also
respect the dependency to CONFIG_XFRM for the IPSEC flag.

Cc: Fan Du <fan.du@windriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update pktgen.txt for reference when using IPsec.
Signed-off-by: NFan Du <fan.du@windriver.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

This patch increases the granularity of the rate generated by pktgen.
The previous version of pktgen uses micro seconds (udelay) resolution when it
was delayed causing gaps in the rates. It is changed to nanosecond (ndelay).
Now any rate is possible.

Also it allows to set, the desired rate in Mb/s or packets per second.

The documentation has been updated.
Signed-off-by: NDaniel Turull <daniel.turull@gmail.com>
Signed-off-by: NRobert Olsson <robert.olsson@its.uu.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is not currently possible to instruct pktgen to use one selected tx queue.

When Robert added multiqueue support in commit 45b270f8, he added
an interval (queue_map_min, queue_map_max), and his code doesnt take
into account the case of min = max, to select one tx queue exactly.

I suspect a high performance setup on a eight txqueue device wants
to use exactly eight cpus, and assign one tx queue to each sender.

This patchs makes pktgen select the right tx queue, not the first one.

Also updates Documentation to reflect Robert changes.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NRobert Olsson <robert.olsson@its.uu.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes typos in various Documentation txts. The patch addresses some
misc words.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

This patch fixes typos in various Documentation txts. The patch addresses some
+words starting with the letter 'T'.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

This patch fixes typos in various Documentation txts. The patch addresses
some words starting with the letters 'H'-'M'.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

This patch fixes typos in various Documentation txts. This patch addresses
some words starting with the letters 'D'-'E'.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

This patch fixes typos in various Documentation txts.
This patch addresses some words starting with the letter 'A'.
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NFrancesco Fondelli <francesco.fondelli@gmail.com>
Signed-off-by: NRobert Olsson <robert.olsson@its.uu.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Three typos in only one line...
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NSteven Whitehouse <steve@chygwyn.com>
Signed-off-by: NRobert Olsson <robert.olsson@its.uu.se>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!