RE: recent changes to writable page tables on -unstable andxend

RE: recent changes to writable page tables on -unstable andxend

[Ian Pratt]

 
> Any thought on which of the recent writable pagetable changes 
> could be causing an update to fail where it succeeded on xen 
> 6 days ago?

As I recall, we were taking the emulation path every time until quite
recently. Are you sure you were actually using writeable pagetables
before?

You probably want to augment the debug message to print out a bit more
about the old and new pte, page type, and which pages are in wrpt mode.

Ian

Re: recent changes to writable page tables on -unstable andxend

[Kip Macy]

> As I recall, we were taking the emulation path every time until quite
> recently. Are you sure you were actually using writeable pagetables
> before?

Well, last week I spent an hour or two removing places where FreeBSD
blew up when it tried to write directly to a page directory because
previously I didn't differentiate between PD and PT updates and today
when I removed the WRITABLE_PAGETABLES define the code initially
wouldn't compile. I can test out a tree from as of my checkin, but I'm
fairly positive.

> You probably want to augment the debug message to print out a bit more
> about the old and new pte, page type, and which pages are in wrpt mode.

Ok, I'll do that thanks.

                                -Kip