HEADS-UP: IFLIB implementations of sys/dev/e1000 em, lem, igb pending

[Sean Bruno]

On 01/23/17 08:39, Olivier Cochard-Labbé wrote:
> 
> On Thu, Jan 12, 2017 at 1:54 AM, Matthew Macy <mmacy at nextbsd.org
> <mailto:mmacy at nextbsd.org>> wrote:
> 
>      >  A flame graph for the core cycle count and a flame graph with
>     cache miss stats from pmc would be a great start.
>      >
>      >
>      > ​I didn't know the exact event name to use for cache miss stats,
>     but here are the flame graphs for CPU_CLK_UNHALTED_CORE:
>      > http://dev.bsdrp.net/netgate.r311848.CPU_CLK_UNHALTED_CORE.svg
>     <http://dev.bsdrp.net/netgate.r311848.CPU_CLK_UNHALTED_CORE.svg>
>      > http://dev.bsdrp.net/netgate.r311849.CPU_CLK_UNHALTED_CORE.svg
>     <http://dev.bsdrp.net/netgate.r311849.CPU_CLK_UNHALTED_CORE.svg>
> 
>     Thanks. Having twice as many txqs would definitely help. It's also
>     clear that there may be some sort of peformance issue in
>     iflib_txq_drain. Although it could just be non-stop cache misses on
>     the packet headers.
> 
> 
> ​Any news about the performance issue in iflib_txq_drain ?
> 
> On a different hardware (PC Engine APU2), I've got -20% performance drop:
> 
> x head r311848: packets per second
> + head r311849: packets per second
> +--------------------------------------------------------------------------+
> | ++                                                                      x|
> |+++                                                                 x xx x|
> |                                                                     |_A_||
> ||A|                                                                       |
> +--------------------------------------------------------------------------+
>     N           Min           Max        Median           Avg        Stddev
> x   5        580021        588650        585676      585406.1     3550.8673
> +   5        463865        467599        465428      465638.6     1437.9347
> Difference at 95.0% confidence
>         -119768 +/- 3950.78
>         -20.4589% +/- 0.558328%
>         (Student's t, pooled s = 2708.9)
> ​
>  
> ​Because it's an AMD processor I didn't found the pmc equivalent of
> CPU_CLK_UNHALTED_CORE, then I've used BU_CPU_CLK_UNHALTED but I've no
> idea if it's the good one.
> 
> http://dev.bsdrp.net/apu2.r311848.BU_CPU_CLK_UNHALTED.svg
> http://dev.bsdrp.net/apu2.r311849.BU_CPU_CLK_UNHALTED.svg
> ​
> ​Thanks​
> 
> 


Olivier:

Which set of configs from your test suite are you using for this?
Specifically, what packet size are you slamming across?

https://github.com/ocochard/netbenches/tree/master/pktgen.configs

sean

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 618 bytes
Desc: OpenPGP digital signature
URL: <http://lists.freebsd.org/pipermail/freebsd-net/attachments/20170123/790e52ed/attachment.sig>