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

Daniel Phillips
2001-08-27T18:58:26Z

On August 27, 2001 08:37 pm, Oliver Neukum wrote:
> Hi,
>
> > - Readahead cache is naturally a fifo - new chunks of readahead
> > are added at the head and unused readahead is (eventually)
> > culled from the tail.
>
> do you really want to do this based on pages ? Should you not drop all
> pages associated with the inode that wasn't touched for the longest
> time ?

Isn't that very much the same as dropping pages from the end of the readahead
queue?

> If you are streaming dropping all should be no great loss.

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.

--
Daniel