Re: [resent PATCH] Re: very slow parallel read performance

Richard Gooch
2001-08-27T19:55:38Z

Daniel Phillips writes:
> The quesion is, how do you know you're streaming? Some files are
> read/written many times and some files are accessed randomly. I'm
> trying to avoid penalizing these admittedly rarer, but still
> important cases.

I wonder if we're trying to do the impossible: an algorithm that works
great for very different workloads, without hints from the process.

Shouldn't we encourage use of madvise(2) more? And if needed, add
O_DROPBEHIND and similar flags for open(2).

The application knows how it's going to use data/memory. It should
tell the kernel so the kernel can choose the best algorithm.

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca