Re: [PATCH 2/3] x86: add a is_e820_ram() helper

[Christoph Hellwig <hch@lst.de>]

On Thu, Mar 26, 2015 at 05:49:38PM +0200, Boaz Harrosh wrote:
> > +	memmap=nn[KMG]!ss[KMG]
> > +			[KNL,X86] Mark specific memory as protected.
> > +			Region of memory to be used, from ss to ss+nn.
> > +			The memory region may be marked as e820 type 12 (0xc)
> > +			and is NVDIMM or ADR memory.
> > +
> 
> Do we need to escape "\!" this character on grub command line ? It might
> help to note that. I did like the original "|" BTW

No need to escape it on the kvm command line, which is where I tested
this flag only so far.  If there is a strong argument for "|" I'm happy
to change it.

> > +#define E820_PRAM	12
> 
> Why the PRAM Name. For one 2/3 of this patch say PMEM the Kconfig
> to enable is _PMEM_, the driver stack that gets loaded is pmem,
> so PRAM is unexpected.
> 
> Also I do believe PRAM is not the correct name. Yes NvDIMMs are RAM,
> but there are other not RAM technologies that can be supported exactly
> the same way.
> MEM is a more general name meaning "on the memory bus". I think.
> 
> I would love the consistency.

Ingo asked for the PRAM name, I don't really care either way.

> > +	case E820_PRAM:
> > +		printk(KERN_CONT "persistent (type %u)", type);
> 
> This case can only mean 12 in this patch. (I think historically
> you had a Kconfig to set its Number

Indeed.  I kept it in case people hack their kernels, but I can remove
it if people feel it's too ugly.