Date: Tue, 29 Jan 2008 09:41:53 -0800
From: Yinghai Lu <Yinghai.Lu@Sun.COM>
Subject: Re: [PATCH 2/2] x86_64: make early_node_mem return align address
In-reply-to: <200801291033.29871.ak@suse.de>
To: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>, Christoph Lameter <clameter@sgi.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Message-id: <200801290941.54145.yinghai.lu@sun.com>
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On Tuesday 29 January 2008 01:33:29 am Andi Kleen wrote:
> On Tuesday 29 January 2008 10:05, Yinghai Lu wrote:
> > [PATCH 2/2] x86_64: make early_node_mem return align address
> >
> > boot oops when system get 64g or 128g installed
> 
> Probably it should just use reserve_early(). Does this patch work?
>  
> The alignment change is needed at some point too, but only to 
> relax the alignment to not force all early allocations to be page
> padded.

No, my patch doesn't force all early allocations to be page padded.
for find_e820_mem, i just change PAGE_ALIGN to be aligned align parameter....

only make early_node_mem have aligned data. because it seems it like to...and assume that.

I think your patch will get early panic about overlap between bss and bootmem...
like the 256g machine, bss is overlapped with early page table...

so could change 

-???????node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size);
+???????node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
+??????????????????????????????????????? ? ZONE_ALIGN);

===>

-       node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size);
+       node_data[nodeid] = early_node_mem(nodeid, start, end, pgdat_size,
+                                          PAGE_SIZE);


or

-???????if (mem != -1L)
+???????if (mem != -1L) {
+???????????????mem = round_up(mem, PAGE_SIZE);
????????????????return __va(mem);
+???????}

YH

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