Mike Fedyk wrote:
>
> > echo file_readahead:N > /proc/ide/ide0/hda/settings
> >
> > where N is in kilobytes in 2.4.16 kernels.
>
> Any idea which drivers it will/won't work on? ie, "almost all ide" or
> "almost none of the ide driers"?
It appears that all IDE is controlled with /proc/ide/ide0/hda/settings
> >In earlier kernels
> > it's kilopages (!).
>
> Isn't this part of the max-readahead patch?
No, that fix went in separately. Roger Larsson created it, then
I hit the same problem and forwarded Roger's patch to the relevant
parties.
> Does /proc/sys/vm/max_readahead affect scsi in any way?
Well, `grep -r max_readahead drivers/scsi' comes up blank,
so it looks like the scsi drivers don't implement the
driver-specific readhead tunable, and so they will fall back
to the /proc/sys/vm/max_readahead global. I guess.
> What layer does /proc/sys/vm/max_readahead affect? Block? FS?
The generic filesystem library code. The bit which sits
on top of the block layer and gets its block mappings from the
filesystem and does generic_file_readahead(). Variously
referred to as VFS or VM. It's neither, and both, really.
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This archive was generated by hypermail 2b29 : Fri Nov 30 2001 - 21:00:29 EST