On Mon, 7 Oct 2002, Daniel Phillips wrote:
>
> Devices have a few MB of readahead cache, the kernel can have thousands of
> times as much.
I don't think that is in the least realistic.
There's _no_ way that the krenel could do physical readahead for more than
a few tens or hundreds of kB - the latency impact would just be too much
to handle, and the VM impact is not likely insignificant either.
So the device readahead is _not_ noticeably smaller than what the kernel
can reasonably do, and it does a better job of it (ie disks can fill track
buffers optimally, depending on where the head hits etc).
Linus
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Oct 07 2002 - 22:01:00 EST