Re: [PATCH] gurantee DMA area for alloc_bootmem_low()

[Yasunori Goto <y-goto@jp.fujitsu.com>]

> > To avoid this panic, following patch skips no DMA'ble node when 
> > lower address is required.
> > I tested this patch on my Tiger 4 and our new server.
> 
> Seems reasonable ... but do you not want to check that the returned
> ptr is actually less than MAX_DMA_ADDRESS as well? 

Well... If there isn't enough DMA area in a node by too much
lower memory request or by something strange memory map in the node,
its case might occur.
I don't know it will really happen. But, the after check might be better
than nothing.

To tell the truth, I did the after check at first
"instead of" previous check like this patch. 
In its patch, if its DMA check failed, 
allocated area are should be freed by free_bootmem_core(). 
But hung up occurred by it, and I changed my patch to previous check
instead of deep investigation of its hung up.

Ok. I'll investigate more.

Thanks.
-- 
Yasunori Goto