[RFC 2/2] arm: Get rid of meminfo

[Catalin Marinas]

On Wed, Jan 15, 2014 at 10:53:47AM +0000, Russell King - ARM Linux wrote:
> On Wed, Jan 15, 2014 at 10:22:02AM +0000, Catalin Marinas wrote:
> > On 15 January 2014 09:49, Russell King - ARM Linux
> > <linux at arm.linux.org.uk> wrote:
> > > On Tue, Jan 14, 2014 at 09:55:22PM -0800, Laura Abbott wrote:
> > >> memblock is now fully integrated into the kernel and is the prefered
> > >> method for tracking memory. Rather than reinvent the wheel with
> > >> meminfo, migrate to using memblock directly instead of meminfo as
> > >> an intermediate.
> > >
> > > The reason I never killed meminfo was that for some of the functions here
> > > is that meminfo has a slightly different property to memblock.
> > >
> > > With meminfo, each sparsemem section mapping or discontigmem node must be
> > > specified as a separate bank of memory, even if it is contiguous with the
> > > previous block.  This is so that the functions which walk the page arrays
> > > can do so efficiently (without having to convert from a PFN to a struct
> > > page for every page in the system, which is very inefficient.)
> > 
> > pfn_to_page() conversion is indeed expensive with sparsemem (on
> > 32-bit) but does meminfo actually add a noticeable improvement to the
> > boot time? I don't think so but it's worth testing (something a
> > thousand cycles maximum would be lost in the noise).
> 
> Why do you ask about boot time?

Is meminfo used on a critical path at run-time?

-- 
Catalin