Messages in this thread | | | Date | Tue, 28 Jan 2014 18:22:30 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH 1/3] memblock, nobootmem: Add memblock_virt_alloc_low() |
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On Tue, Jan 28, 2014 at 12:23:02PM -0500, Santosh Shilimkar wrote: > On Tuesday 28 January 2014 12:12 PM, Yinghai Lu wrote: > > Index: linux-2.6/include/linux/bootmem.h > > =================================================================== > > --- linux-2.6.orig/include/linux/bootmem.h > > +++ linux-2.6/include/linux/bootmem.h > > @@ -179,6 +179,9 @@ static inline void * __init memblock_vir > > NUMA_NO_NODE); > > } > > > > +/* Take arch's ARCH_LOW_ADDRESS_LIMIT at first*/ > > +#include <asm/processor.h> > > + > > #ifndef ARCH_LOW_ADDRESS_LIMIT > > #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL > > #endif > > This won't help mostly since the ARM 32 arch don't set ARCH_LOW_ADDRESS_LIMIT. > Sorry i couldn't respond to the thread earlier because of travel and > don't have access to my board to try out the patches.
Let's think about this for a moment, shall we...
What does memblock_alloc_virt*() return? It returns a virtual address.
How is that virtual address obtained? ptr = phys_to_virt(alloc);
What is the valid address range for passing into phys_to_virt() ? Only lowmem addresses.
Hence, having ARCH_LOW_ADDRESS_LIMIT set to 4GB-1 by default seems to be completely rediculous - and presumably this also fails on x86_32 if it returns memory up at 4GB.
So... yes, I think reverting the arch/arm part of this patch is the right solution, whether the rest of it should be reverted is something I can't comment on.
-- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit".
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