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  1. 12 Aug, 2021 4 commits
    • David S. Miller's avatar
      Merge branch 'pktgen-imix' · 445af0d2
      David S. Miller authored 
      Nick Richardson says:

====================
pktgen: Add IMIX mode

Adds internet mix (IMIX) mode to pktgen. Internet mix is
included in many user-space network perf testing tools. It allows
for the user to specify a distribution of discrete packet sizes to be
generated. This type of test is common among vendors when perf testing
their devices.
[RFC link: https://datatracker.ietf.org/doc/html/rfc2544#section-9.1]

This allows users to get a
more complete picture of how their device will perform in the
real-world.

This feature adds a command that allows users to specify an imix
distribution in the following format:
  imix_weights size_1,weight_1 size_2,weight_2 ... size_n,weight_n

The distribution of packets with size_i will be
(weight_i / total_weights) where
total_weights = weight_1 + weight_2 + ... + weight_n

For example:
  imix_weights 40,7 576,4 1500,1

The pkt_size "40" will account for 7 / (7 + 4 + 1) = ~58% of the total
packets sent.

This patch was tested with the following:
1. imix_weights = 40,7 576,4 1500,1
2. imix_weights = 0,7 576,4 1500,1
  - Packet size of 0 is resized to the minimum, 42
3. imix_weights = 40,7 576,4 1500,1 count = 0
  - Zero count.
  - Runs until user stops pktgen.
Invalid Configurations
1. clone_skb = 200 imix_weights = 40,7 576,4 1500,1
    - Returns error code -524 (-ENOTSUPP) when setting imix_weights
2. len(imix_weights) > MAX_IMIX_ENTRIES
    - Returns -7 (-E2BIG)

This patch is split into three parts, each provide different aspects of
required functionality:
  1. Parse internet mix input.
  2. Add IMIX Distribution representation.
  3. Process and output IMIX results.

Changes in v2:
* Remove __ prefix outside of uAPI.
* Use seq_puts instead of seq_printf where necessary.
* Reorder variable declaration.
* Return -EINVAL instead of -ENOTSUPP when using IMIX with clone_skb > 0
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      445af0d2
    • Nick Richardson's avatar
      pktgen: Add output for imix results · 769afb3f
      Nick Richardson authored 
      The bps for imix mode is calculated by:
sum(imix_entry.size) / time_elapsed

The actual counts of each imix_entry are displayed under the
"Current:" section of the interface output in the following format:
imix_size_counts: size_1,count_1 size_2,count_2 ... size_n,count_n

Example (count = 200000):
imix_weights: 256,1 859,3 205,2
imix_size_counts: 256,32082 859,99796 205,68122
Result: OK: 17992362(c17964678+d27684) usec, 200000 (859byte,0frags)
  11115pps 47Mb/sec (47977140bps) errors: 0

Summary of changes:
Calculate bps based on imix counters when in IMIX mode.
Add output for IMIX counters.
Signed-off-by: default avatarNick Richardson <richardsonnick@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      769afb3f
    • Nick Richardson's avatar
      pktgen: Add imix distribution bins · 90149031
      Nick Richardson authored 
      In order to represent the distribution of imix packet sizes, a
pre-computed data structure is used. It features 100 (IMIX_PRECISION)
"bins". Contiguous ranges of these bins represent the respective
packet size of each imix entry. This is done to avoid the overhead of
selecting the correct imix packet size based on the corresponding weights.

Example:
imix_weights 40,7 576,4 1500,1
total_weight = 7 + 4 + 1 = 12

pkt_size 40 occurs 7/total_weight = 58% of the time
pkt_size 576 occurs 4/total_weight = 33% of the time
pkt_size 1500 occurs 1/total_weight = 9% of the time

We generate a random number between 0-100 and select the corresponding
packet size based on the specified weights.
Eg. random number = 358723895 % 100 = 65
Selects the packet size corresponding to index:65 in the pre-computed
imix_distribution array.
An example of the  pre-computed array is below:

The imix_distribution will look like the following:
0        ->  0 (index of imix_entry.size == 40)
1        ->  0 (index of imix_entry.size == 40)
2        ->  0 (index of imix_entry.size == 40)
[...]    ->  0 (index of imix_entry.size == 40)
57       ->  0 (index of imix_entry.size == 40)
58       ->  1 (index of imix_entry.size == 576)
[...]    ->  1 (index of imix_entry.size == 576)
90       ->  1 (index of imix_entry.size == 576)
91       ->  2 (index of imix_entry.size == 1500)
[...]    ->  2 (index of imix_entry.size == 1500)
99       ->  2 (index of imix_entry.size == 1500)

Create and use "bin" representation of the imix distribution.
Signed-off-by: default avatarNick Richardson <richardsonnick@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      90149031
    • Nick Richardson's avatar
      pktgen: Parse internet mix (imix) input · 52a62f86
      Nick Richardson authored 
      Adds "imix_weights" command for specifying internet mix distribution.

The command is in this format:
"imix_weights size_1,weight_1 size_2,weight_2 ... size_n,weight_n"
where the probability that packet size_i is picked is:
weight_i / (weight_1 + weight_2 + .. + weight_n)

The user may provide up to 100 imix entries (size_i,weight_i) in this
command.

The user specified imix entries will be displayed in the "Params"
section of the interface output.

Values for clone_skb > 0 is not supported in IMIX mode.

Summary of changes:
Add flag for enabling internet mix mode.
Add command (imix_weights) for internet mix input.
Return -ENOTSUPP when clone_skb > 0 in IMIX mode.
Display imix_weights in Params.
Create data structures to store imix entries and distribution.
Signed-off-by: default avatarNick Richardson <richardsonnick@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      52a62f86
  3. 11 Aug, 2021 36 commits
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