Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 11 Nov 2011 11:58:02 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v8 13/16] ARM: LPAE: Add identity mapping support for the 3-level page table format |
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On Fri, Nov 11, 2011 at 11:36:01AM +0000, Catalin Marinas wrote: > On Thu, Nov 10, 2011 at 10:55:17PM +0000, Russell King - ARM Linux wrote: > > On Mon, Nov 07, 2011 at 04:16:55PM +0000, Catalin Marinas wrote: > > > + pmd += pmd_index(addr); > > > + } else > > > + pmd = pmd_offset(pud, addr); > > > + > > > + do { > > > + next = pmd_addr_end(addr, end); > > > + *pmd = __pmd((addr & PMD_MASK) | prot); > > > + flush_pmd_entry(pmd); > > > + } while (pmd++, addr = next, addr != end); > > > +} > > > +#else /* !CONFIG_ARM_LPAE */ > > > > I'm not convinced about the wiseness of this. One of the places where > > this code is called is from the reboot paths, which can happen in atomic > > context. Trying to allocate memory in such a context is going to lead > > to problems, especially if support for panic'ing on OOM, and rebooting > > on panic'ing are both enabled. > > A solution would be to have pre-set page table for identity mappings > (which may even come in handy for power management) and avoid the > allocation in idmap.c.
Yup, that's what I do in my latest kexec series (v5) so this problem goes away then.
> > Therefore, I think this patch depends on the work Will has been doing to > > re-structure the kexec and restart support. > > I think Will can rebase his patches on top of mine (I touched this file > first :)).
Haha, but my code doesn't depend on yours in order to work correctly!
Will
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