Re: [PATCH] x86: introduce init_memory_mapping for 32bit

From: Ingo Molnar
Date: Wed Jun 25 2008 - 10:46:17 EST



* Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:

> On Tue, Jun 24, 2008 at 4:30 AM, Ingo Molnar <mingo@xxxxxxx> wrote:
> >
> > * Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:
> >
> >> so could use mem below max_low_pfn as early. could move several
> >> function more early instead of waiting after paging_init including
> >> moving relocate_initrd early, and kva related early done in
> >> initmem_init
> >
> > applied to tip/x86/setup-memory - thanks Yinghai.
> >
> > a sidenote:
> >
> >> 6 files changed, 128 insertions(+), 74 deletions(-)
> >
> > this patch is too large - if it causes any problems it will not be very
> > easy to figure out which exact change caused the problems.
> >
> > Lets hope it goes all fine - but in the future lets try doing
> > more+smaller patches, especially if they change some known-dangerous
> > area of the kernel.
> >
> > For example here a better splitup would have been to do 5 or more
> > patches:
> >
> > 1) first introduce init_memory_mapping() [but dont use it anywhere]
> > 2) add the init_memory_mapping() call to setup_arch()
> > 3) move remap_numa_kva()
> > 4) move relocate_initrd()
> > 5) remove the now unnecessary setup from paging_init()
> >
> > ... or something like that. The point is to manage risk: if there's
> > multiple problem areas that a change is touching, try to isolate them
> > from each other and introduce the change gradually.
> >
> > The end result is still exactly the same, but much more
> > reviewable/debuggable/bisectable.
>
> split into 3 patches, please use them to replace the old one if you
> like.

i've applied them to tip/x86/setup-memory, replacing the larger patch -
thanks Yinghai.

Ingo
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