Preliminary review: Adding tracing of I/O calls

[Alan Bateman]

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