Re: posix_fadvise v22

On Thu, Jan 1, 2009 at 3:55 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> "Robert Haas" <robertmhaas(at)gmail(dot)com> writes:
>> Am I correct in thinking that the only thing we're really checking for
>> here is whether a trivial posix_fadvise() call returns success? If
>> so, is this test really worth doing?
>
> Runtime tests performed during configure are generally a bad idea to
> start with --- it's impossible to do any such thing in a
> cross-compilation scenario, for example.

OK, here's an update of Greg's patch with the runtime configure test
ripped out, some minor documentation tweaks, and a few unnecessary
whitespace diff hunks quashed. I think this is about ready for
committer review. The only thing I haven't been able to do is
demonstrate that this change actually produces a performance
improvement. Either I'm testing the wrong thing, or it just doesn't
provide any benefit on a single-spindle system. However, I believe
that Greg has previously posted some fairly impressive performance
results, so I'm not sure that my shortcomings in this area should be a
bar to having a committer pick this one up. If more testing is
needed, it would at least be helpful to have a committer specify what
areas they are concerned about.

...Robert