On Wed, Aug 11, 2004 at 08:50:03AM -0500, Josh Boyer wrote: > On Tue, 2004-08-10 at 09:35, Matt Porter wrote: > > On Tue, Aug 10, 2004 at 02:04:44AM -0400, Dan Malek wrote: > > > > > > On Aug 9, 2004, at 10:21 PM, Josh Boyer wrote: > > > > > > > I have some boards I could test such a patch on. Or is it a case of > > > > "this isn't trivial to do"? > > > > > > Ummmmm.....what are we talking about here? > > > > > > Both MPC8xx, and IBM40x have configuration options for > > > pinning some (small) amount of kernel space. You can choose > > > to enable this if you wish, I don't think it is normally enabled. > > > I've never found a benchmark that proved either was better, > > > but I left the code there for others to experiment with. > > > > PPC40x no longer has this in 2.6. It has been deprecated by the dynamic > > large tlb support. He's looking for an option (like nobats) to cause > > kernel lowmem to not be mapped by large page entries. > > > > So, to answer the original question, I would suggest a patch > > that that uses a 'noltlb' cmdline option, then skips the PPC40x > > large page mapping in 4xx_mmu.c based on that. See the code > > that implements 'nobats' for an example. > > Hm... like this? Against 2.6.8-rc4.
Looks good to me, except we should probably have the cmdline option be 'noltlbs'...minor nit. Please repost after reading http://kerneltrap.org/node/view/3180 and agreeing to the DCO by providing a signed off line. Then it can go into mainline. Thanks, Matt ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
