[Cbe-oss-dev] [PATCH] Fix sparsemem on Cell
akpm at osdl.org
Sat Dec 16 06:45:36 EST 2006
On Fri, 15 Dec 2006 09:24:00 -0800
Dave Hansen <haveblue at us.ibm.com> wrote:
> I think the comments added say it pretty well, but I'll repeat it here.
> This fix is pretty similar in concept to the one that Arnd posted
> as a temporary workaround, but I've added a few comments explaining
> what the actual assumptions are, and improved it a wee little bit.
> The end goal here is to simply avoid calling the early_*() functions
> when it is _not_ early. Those functions stop working as soon as
> free_initmem() is called. system_state is set to SYSTEM_RUNNING
> just after free_initmem() is called, so it seems appropriate to use
Would really prefer not to do this. system_state is evil. Its semantics
are poorly-defined and if someone changes them a bit, or changes memory
initialisation order, you get whacked.
I think an mm-private flag with /*documented*/ semantics would be better.
It's only a byte.
> +static int __meminit can_online_pfn_into_nid(unsigned long pfn, int nid)
I spent some time trying to work out what "can_online_pfn_into_nid" can
possibly mean and failed. "We can bring a pfn online then turn it into a
NID"? Don't think so. "We can bring this page online and allocate it to
this node"? Maybe.
Perhaps if the function's role in the world was commented it would be clearer.
More information about the cbe-oss-dev