Messages in this thread | | | Subject | Re: [PATCH] Fix e820 end address with EFI | From | Huang Ying <> | Date | Tue, 03 Mar 2009 11:06:14 +0800 |
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On Tue, 2009-03-03 at 10:53 +0800, Yinghai Lu wrote: > Huang Ying wrote: > > On Tue, 2009-03-03 at 09:28 +0800, Yinghai Lu wrote: > >> Huang Ying wrote: > >>> On Tue, 2009-03-03 at 05:38 +0800, Yinghai Lu wrote: > >>>> Huang Ying wrote: > >>>>> On Mon, 2009-03-02 at 10:51 +0800, Yinghai Lu wrote: > >>>>>> On Sun, Mar 1, 2009 at 6:37 PM, Huang Ying <ying.huang@intel.com> wrote: > >>>>>>>> so 64bit could use ioremap_cache() too? > >>>>>>>> we may keep 32bit and 64bit a bit consistent. > >>>>>>> If we use ioremap_cache(), kexec runtime service will not work in kexec > >>>>>>> situation, which needs EFI runtime memory area to be mapped at exact > >>>>>>> same location across kexec. I think we should support kexec if possible. > >>>>>> sure. > >>>>>> > >>>>>> please don't touch max_low_pfn_mapped, because some range may not > >>>>>> directly mapped under those efi run-time code > >>>>> Find an issue to use init_memory_mapping() here. > >>>>> > >>>>> If the memory range to be mapped is less than 2M, the last mapped > >>>>> address may be next 2M aligned position, this may lead mapping > >>>>> overlapping between memory range. Such as: > >>>>> > >>>>> 0x3f388000 - 0x3f488000: real mapped 0x3f388000 - 0x3f600000 > >>>>> 0x3f590000 - 0x3f5bb000: real mapped 0x3f590000 - 0x3f600000 > >>>>> > >>>>> The problem is that the memory range 0x3f400000 - 0x3f590000 is left not > >>>>> mapped! > >>>> what is max_low_pfn_mapped before that? > >>> I don't know exactly what you mean. Can you elaborate a little? > >>> > >>> 0 ~ max_low_pfn_mapped ~ max_pfn_mapped can be mapped with > >>> init_memory_mapping() properly. > >>> > >>> The issue of above example is that 0x3f400000 ~ 0x3f488000 is a > >>> sub-range of 0x3f388000 ~ 0x3f488000, which should be mapped but is left > >>> not mapped. > >> what is max_low_pfn_mapped? > >> > >> what is init_memory_mapping() printout? > > > > This does not comes from a real test case. To test the changes I made, I > > make efi_ioremap() being used even if the corresponding memory range is > > below max_low_pfn_mapped. The dmesg of test is attached with the mail. > > > > The printout of init_memory_mapping shows: > > > > init_memory_mapping: 000000003f488000-000000003f4bb000 > > last_map_addr: 3f600000 end: 3f4bb000 > > init_memory_mapping: 000000003f590000-000000003f5bb000 > > last_map_addr: 3f600000 end: 3f5bb000 > init_memory_mapping: 0000000000000000-000000003f700000 > > last_map_addr: 3f700000 end: 3f700000 > > (6 early reservations) ==> bootmem [0000000000 - 003f700000] > > so max_low_pfn_mapped is (3f700000>>12) > and you try to init_memory_mapping again before it
Yes. Just for testing, I want to use efi_ioremap() on more memory range to test.
> > init_memory_mapping: 00000000fffb0000-00000000fffba000 > > last_map_addr: 100000000 end: fffba000 > this one is interesting... got over mapped... > > > > So I think it is possible to have the issue I mentioned above. > > looks like.
So, If you have no time, I can try to fix that. Do you think init_memory_mapping should stop at specified end page?
Best Regards, Huang Ying
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