Interrupt performance

[Stefan Lambrev]

The overhead comes from badly written software.
This software is optimized for linux and you have to optimize it for freebsd, then you will have the same overhead.
All those *popular* benchmarks like hping, iperf, netperf have some strange optimizations for linux - we call them linuxism.
Just search the archives - I'm pretty sure patches are flying around.

On Jan 28, 2011, at 6:10 PM, Slawa Olhovchenkov wrote:

> On Fri, Jan 28, 2011 at 06:03:15PM +0200, Stefan Lambrev wrote:
> 
>> Do the test with netblast ;)
>> Most perf tools are written badly and for Linux.
>> In our internal test netblast running on freebsd outperform everything else.
> 
> I don't speak about bad performance.
> I speak about overhead.
> 
> Linux: overhead 7% for 56K int/s
> FreeBSD: overhead 59% for 14K int/s
> 
> For processing 1/4 interrupts FreeBSD need 8x CPU.
> 
>> P.S. - /usr/src/tools/tools/netrate/netblast - we have tested little more expensive card - em/igb and bce.
>> 
>> On Jan 28, 2011, at 4:33 PM, Slawa Olhovchenkov wrote:
>> 
>>> I test network performance and found some strange result -- on the
>>> same hardware Linux more then 10x used CPU resources for interrupt
>>> processing.
>>> 
>>> FreeBSD system utilise 70% CPU (32% idle, 59% interrupt, 9% sys) and
>>> network card generate 14K-18K interrupt per second.
>>> 
>>> Linux system utilise 20% CPU (80% idle, 13% system, 3% hiq, 4% siq)
>>> and network card generate 56K interrupt per second.
>>> 
>>> I used 'netperf -H host -t UDP_STREAM -l 60 -C -c -- -m 8972 -s
>>> 128K -S 128K' for generate network traffic.
>>> 
>>> NIC:
>>> 
>>> re0: <RealTek 8169SC/8110SC Single-chip Gigabit Ethernet> port 0x4000-0x40ff mem 0xf0100000-0xf01000ff irq 19 at device 4.0 on pci11
>>> re0: Chip rev. 0x18000000
>>> re0: MAC rev. 0x00000000
>>> miibus0: <MII bus> on re0
>>> rgephy0: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus0
>>> 
>>> 
>>> CPU:
>>> 
>>> CPU: Intel(R) Celeron(R) CPU          420  @ 1.60GHz (1596.05-MHz K8-class CPU)
>>> Origin = "GenuineIntel"  Id = 0x10661  Family = 6  Model = 16
>>> Stepping = 1
>>> Features=0xafebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,TM,PBE>
>>> Features2=0xe31d<SSE3,DTES64,MON,DS_CPL,TM2,SSSE3,CX16,xTPR,PDCM>
>>> AMD Features=0x20100800<SYSCALL,NX,LM>
>>> AMD Features2=0x1<LAHF>
>>> TSC: P-state invariant
>>> 
>>> RAM: one DDR2-667 DIMM.
>>> 
>>> OS: 8.2-RC2, amd64
>>> 
>>> _______________________________________________
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>> 
>> --
>> Best Wishes,
>> Stefan Lambrev
>> ICQ# 24134177
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> freebsd-performance at freebsd.org mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-performance
>> To unsubscribe, send any mail to "freebsd-performance-unsubscribe at freebsd.org"

--
Best Wishes,
Stefan Lambrev
ICQ# 24134177