RE: [RFC] 4-level page table directories.

Chen, Kenneth W
2005-11-09T01:18:23Z

Magenheimer, Dan wrote on Tuesday, November 08, 2005 4:46 PM
> Not completely bogus. Flexibility always leads to combinatorial
> explosion, yet OSVs still support a wide variety of devices,
> filesystems, GUIs, etc. Exposing the ability to more easily
> change pagesize is just one more degree of flexibility.

I think you are mixing the argument here. Single kernel image does
not equate to better/easier OSD/ISV certification. I boot this
fancy-one-image-handle-all-cases kernel with half a dozen special
boot time arguments that changes page-size, xen, numa, cpuset,
scheduler parameters. And then call up the ISV and ask for support,
are they going to support that special configuration? Referring
to Rohit Seth's earlier point: ISV is going to say: "we don't support
that configuration, boot without any boot time argument and call back".

I don't see how ISV/OSD's certification job is any easier. Perhaps,
even harder because unless one covers the entire permutation of all
the options, it will never be complete.

Having a flexibility does not automatically grant you certification
for all configurations unless someone spend the time and effort in
validating them all. There is no shortcut here.

- Ken