[Lustre-devel] read ahead

[chas williams - CONTRACTOR]

In message <20071211234708.GT3214 at webber.adilger.int>,Andreas Dilger writes:
>For random reads the code does understand the difference between e.g.
>reads of 16 sequential pages (64kB generally) read at non-consecutive
>offsets and 16 sequential 4kB page reads.  The former will NOT start
>readahead, while the latter does.

what about direct i/o?  it looks like doing direct i/o to a file
will never trigger readahead.  is this intentional?