Preliminary review: Adding tracing of I/O calls (original) (raw)

Alan Bateman Alan.Bateman at oracle.com
Wed Nov 7 14:15:24 UTC 2012

On 07/11/2012 12:55, Staffan Larsen wrote:

:

Negative values means that my changes added a regression. I think most of these values are within the margin of error in the measurements. The one exception is FileChannelRead. I've rerun this many times and it looks fairly consistent around a 4% regression. Why there is only a regression when reading from a FileChannel, I don't know. It's possible that the additional instructions cause a threshold for inlining to be exceeded, would require looking at the compiler diagnostic output or generated code to see. I'll bet it is only obvious on the read because the it's already in the file cache, if there was actual disk access involved then its unlikely to be observable.

-Alan

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