L4Linux-2.6.14 perfomance question
Der Herr Hofrat
der.herr at hofr.at
Wed Dec 7 21:39:04 CET 2005
HI !
I'm very new to L4Linux so my question might be obvious - anyway did not
find anything directly related in the archive. For a start I did a quick
performance comparison using lmbench-3.0.
This comparison is based on the L4Linux-2.6 running a debina ramdisk
lmbench-3.0 vs Linux-2.6.14 running from harddisk (though data files
were in tempfs in both cases - so the HD should not really have much
of an impact).
L4Linux Linux 2.6.14
com lat.: (us)
lat_pipe 14.1-14.5 2.0
lat_fifo 13.9-14.6 2.2
lat_unix 19.4-19.5 3.2
lat_sem 3.5 0.6
lat_proc: (us)
fork 805-1249 80-82
exec 3124-3784 212-230
shell 9992-9997 2480-2592
tlb: 7,8,32 always 32
bw com: (MB/s)
bw_pipe 921-958 1338-1352
bw_unix 429-753 1122-1138
lat mem: oopses under L4Linux - no results
bw_mem: (MB/s)
bcopy 3856-4066 5056-5080
rdwr 11937-13242 16052
syscall: (us)
null 2.4-2.8 0.13
read 2.6-3.3 0.26-0.31
stat 4.4-4.9 0.89
open 6.5-8.1 1.16-1.39
The thing that supprises me is that the performance variation is much
higher than on regular linux - in both cases the system was idle except
for lmbench running, so I'm excluding any syslog parties or cron jobs
fireing at inconvenient times (i.e bandwidth of UNIX sockets has a variance
of almost 50% ?). Generally the performance difference is much larger
than I would have expected, especially also in areas where I don't quite
understand where the u-kenrel can impact the Linux system (i.e. bcopy,
memory read-write)
Are these values in the usual range or did I screw up fundamentally ?
thx !
Prof. Nicholas Mc Guire University of Lanzhou
Distributed & Embedded System Lab http://dslab.lzu.edu.cn
School of Information Science and Engeneering mcguire at lzu.edu.cn
Tianshui South Road 222. Lanzhou 730000 .P.R.China
Tel:+86-931-8912025 Fax:+86-931-8912022
Lichtensteinstr. 31, Mistelbach A-2130 Austria
Tel:+43-2572-201082 Fax:+43-2572-201084
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