Re: [PATCH 3/8] sparc: prom: use property "name" directly to construct node names

[David Miller]

From: Rob Herring <robh@xxxxxxxxxx>
Date: Fri, 9 Nov 2018 07:02:46 -0600

> On Thu, Nov 8, 2018 at 9:13 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
>>
>> From: Rob Herring <robh@xxxxxxxxxx>
>> Date: Wed,  7 Nov 2018 16:31:46 -0600
>>
>> > In preparation to remove direct accesses to the device_node.name
>> > pointer, retrieve the node name from the "name" property instead.
>> >
>> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
>> > Cc: sparclinux@xxxxxxxxxxxxxxx
>> > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
>>
>> On some 32-bit sparcs, the OF runs in non-cached memory.
>>
>> Sucking in the OF device tree take a signficant amount of the
>> boot time on such systems.
>>
>> And these changes are going to make it even slower.
>>
>> Please just put a wrapper around dp->name or whatever and use that,
>> instead of making more get property OF calls which can be very
>> expensive.
> 
> It's not making calls into OF. It is retrieving the property from the
> kernel's copy of the DT (allocated by memblock). So the only
> difference is we have to walk the struct property list to find "name".
> That's perhaps offset by the fact that we'll be doing one less
> property retrieval from OF when this is all done. Right now, we
> retrieve "name" from OF twice per node.

Ok, now I understand, thanks.