On 01/23/17 08:39, Olivier Cochard-Labbé wrote: > > On Thu, Jan 12, 2017 at 1:54 AM, Matthew Macy <mm...@nextbsd.org > <mailto:mm...@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
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