2:05 p.m.
On Tue, Apr 28, 2015 at 1:57 PM, Dan Williams <dan.j.williams(a)intel.com> wrote:
On Tue, Apr 28, 2015 at 1:49 PM, Andy Lutomirski
<luto(a)amacapital.net> wrote:
> On Tue, Apr 28, 2015 at 11:24 AM, Dan Williams <dan.j.williams(a)intel.com>
wrote:
>> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
>> index 11cc7d54ec3f..d38b53a7e9b2 100644
>> --- a/arch/x86/kernel/e820.c
>> +++ b/arch/x86/kernel/e820.c
>> @@ -149,6 +149,7 @@ static void __init e820_print_type(u32 type)
>> case E820_UNUSABLE:
>> printk(KERN_CONT "unusable");
>> break;
>> + case E820_PMEM:
>> case E820_PRAM:
>> printk(KERN_CONT "persistent (type %u)", type);
>> break;
>
> I'd kind of like to make it more clear what's going on here. It
> doesn't help that the spec chose poor names.
>
> How about "NVDIMM physical aperture" for E820_PMEM and "legacy
> persistent RAM" for E820_PRAM?
The term "aperture" to me implies this BLK (mmio-windowed) mode of
accessing persistent media that the NFIT specification introduces. In
fact, those ranges are mapped E820_RESERVED. E820_PMEM really is a
memory range that happens to be persistent.
Oh, I missed that. Yuck. What happens when you repartition one of
these things? (Can you even do that?)
> Otherwise this looks generaly sensible, although I don't really
> understand why e820_type_to_string and e820_print_type are different.
e820_type_to_string() appears in /proc/iomem and seems to afford
being more descriptive than e820_print_type() that just scrolls by in
dmesg, but I'm just guessing.
Can we change that?
--
Andy Lutomirski
AMA Capital Management, LLC