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Message-ID: <86802c440806241016l2baf05b9le356fdc314a2af9@mail.gmail.com>
Date: Tue, 24 Jun 2008 10:16:29 -0700
From: "Yinghai Lu" <yhlu.kernel@gmail.com>
To: "Ingo Molnar" <mingo@elte.hu>
Subject: Re: [PATCH] x86: introduce init_memory_mapping for 32bit
Cc: "Thomas Gleixner" <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Tue, Jun 24, 2008 at 4:30 AM, Ingo Molnar <mingo@elte.hu> wrote:
>
> * Yinghai Lu <yhlu.kernel@gmail.com> 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.

actually i added and tested that one by one. let me check if i split
that into 5.

YH