> -----Original Message----- > From: Hollis Blanchard [mailto:hollisb@xxxxxxxxxx] > Sent: Wednesday, May 28, 2008 10:24 PM > To: Liu Yu > Cc: kvm-ppc@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] Fix kvmppc_mmu_invalidate bug > > On Tuesday 27 May 2008 22:03:32 Liu Yu wrote: > > > > > > Did you discover this through inspection, or do you have a guest > > > that triggers this bug? I don't believe there is large > page support > > > for e500 Linux userspace (and the kernel mappings don't ever need > > > invalidation)? > > > > > > > I discovered it through inspection. As recently I'm porting > your code > > for > E500. > > E500 support the instruction tlbiva, so I have to read this part of > > your > code carefully. > > Ah, OK. I will commit your patch soon, but I do need to > update the tree and clean up a number of half-working patches > we tried in order to get good performance for a demo. :) Great. I'm looking forward to read them. > > > Yes. E500 doesn't have large mapping in userspace. Neither > does 44x, right? > > Yes, but there is a patch that increases the base page size > from 4K to 64K. > We've played with this on the host to reduce the number of > host TLB misses when emulating the large guest kernel > mapping, and eventually we should try it in the guest too. > > Unfortunately the 64K patch has another issue: it > dramatically increases memory allocations. On our 256MB > boards we could boot ELDK fine, but actually ran out of > memory trying to boot Ubuntu (on the host).. Hmm, it seems increase the memory waste. BTW: How did you make Ubuntu run on 44x? Doesn't Ubuntu just support classical powerpc? ��.n��������+%������w��{.n�����o��^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�m
