Messages in this thread |  | | | Subject | benchmarks of O_STREAMING in 2.5 | | From | Robert Love <> | | Date | 16 Oct 2002 22:53:20 -0400 |
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I gave the O_STREAMING in Andrew's 2.5-mm tree the treatment..
Short summary: It works.
The streaming read test in the following benchmarks is simply a read() in 64KB byte chunks of an 800MB file.
First test. Show the cache effects are indeed as we intend and the overhead is negligible. Here, mem=2G.
O_STREAMING? Wall time Cache Delta Yes 21.827s 0 No 21.734s +800MB
Second test. Same deal, but mem=8M. There was slight swapping, so I suspect the reduced VM pressure is why the O_STREAMING run is faster.
O_STREAMING? Wall time Cache Delta Yes 22.303s 0 No 28.812s +1MB
Third and final test. Kernel compile (make -j2) with a couple streaming reads in the background. Again, mem=2G. This shows that actually saving the pagecache from the horrid waste is useful.
O_STREAMING Wall time to complete Kernel compile Yes 5m30.494s No 4m59.661s
So, uh, Andrew's 2.5 code works ;-)
Someone buy me a dual Xeon,
Robert Love
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