Messages in this thread | | | Date | Fri, 06 Jul 2007 13:34:21 -0700 | From | Zachary Amsden <> | Subject | Re: [PATCH] VMI: remove CONFIG_DEBUG_PAGE_TYPE and associated bitrotted code |
| |
Jeremy Fitzhardinge wrote: >> >> I never merged the whole bit upstream because it added a field to >> struct page. > > Hm, is that a big problem? It would be OK for a debug config option, > wouldn't it? Also, it doesn't seem particularly vmi-specific. Could > it be made part of the pvops infrastructure?
I though about it, but it gets really ugly. You need wrappers for all the MMU ops in pvops generic code, which means either another layer of wrappers or a bunch of CONFIG_DEBUG_PARAVIRT only things that are easy to break because they also depend on PAE vs. non-PAE.
It's doable, though, and might even be extensible to s390 for CMM page type debugging, as well as descriptor type tracking and enforcement of page isolation of GDTs.
Page state tracking could track -
PAGE_ZERO, PAGE_UNUSED, PAGE_STABLE, PAGE_VOLATILE, PAGE_POTENTIALLY_VOLATILE, PAGE_L1{2/3/4}, PAGE_LDT, PAGE_GDT,
actually, no this seems silly, since we'd just be duplicating bits for the page types, so the only debug benefit is ensuring the intersection of volatile and L{1/2/3/4} is nil, which is already trivially verifiable by inspection.
Zach - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |