Hi, On Wed, Jan 30, 2008 at 02:57:16AM -0800, Paul E. McKenney wrote: ...... > > Yes, I used "$ cyclictest -n -t1 -p80 -i1000" to measure the latency. So > > far, I have not done other tests. Any recommendation? > > As no-rt load I used "while ls; do ls /bin; done" in one telnet window > > and "while ./hackbench 10; do ./calibrator 400 32M cali; sleep 30; done" > > in another. But already "while ls; do ls /bin; done" is enough to > > trigger the high latencies quickly. Note also, that I work on a root > > files-ystem mounted via NFS resulting in a lot of network traffic and > > utilization. > > I have to ask... > > Did you see large latencies when -not- running on NFS? > I cannot speak for Wolfgang but I myself did not get extraordinary high latencies running tests on system booted from flash. Neither I could produce high latencies on nfs booted system. If my non-rt workload doesn't do heavy filesystem/network accesses. i.E. running only hackbench. Hence we were wondering if the problem is caused by rcu's in network layer or nfs implementation. regards Luotao Fu -- Dipl.-Ing. Luotao Fu | Phone: +49-5121-206917-3 Pengutronix - Linux Solutions for Science and Industry Entwicklungszentrum Nord http://www.pengutronix.de
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