Messages in this thread | | | Date | Sat, 20 Apr 2002 19:14:19 +0900 (JST) | Subject | Re: [PATCH] zerocopy NFS updated | From | Hirokazu Takahashi <> |
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Hi,
> With all this talk on serialization on UDP, and have a question. first, let > me explain the situation. I have an NFS test which calls 48 clients to read > the same 200 MB file on the same server. I record the time for all the > clients to finish and then calculate the total throughput. The server is a > 4-way IA32. (I used this test to measure the zerocopy/tcp/nfs patch) Now, > right before the test, the 200 MB file is created on the server, so there is > no disk IO at all during the test. It's just an very simple cached read. > Now, when the clients use udp, I can only get a run queue length of 1, and I > have confirmed there is only one nfsd thread in svc_process() at one time, > and I am 65% idle. With tcp, I can get all nfsd threads running, and max all > CPUs. Am I experiencing a bottleneck/serialization due to a single UDP > socket?
What version do you use? 2.5.8 kernel has a problem in readahead of NFSD. It doesn't work at all.
It can be easy to fix.
Thank you, Hirokazu Takahashi. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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