Messages in this thread | | | From | Tabi Timur-B04825 <> | Subject | Re: [RFC PATCH 02/17] powerpc: Split up PHYS_64BIT config option to fix "select" issues | Date | Fri, 11 Nov 2011 13:12:31 +0000 |
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Benjamin Herrenschmidt wrote:
> For PHYS_64BIT, I'm not 100% certain at this point what the best > approach it. It should clearly be fixed and hidden for real 64-bit. As > for the rest, should it be user selectable ?
I have been unable to convince our BSP teams that the minor performance improvement of a 32-bit kernel vs 36-bit is not worth the hassle. We ship a lot of lower-end e500 systems that will never have more than 2GB of memory.
The P1022DS is an example. We ship 32-bit and 36-bit versions of U-Boot, the kernel, and the device tree. I recently added code to U-boot to detect if you have a mismatched U-Boot and device tree, because it is so easy to mess that up. I would like nothing more than to abandon 32-bit for all e500, but I don't see Freescale allowing that any time soon.
-- Timur Tabi Linux kernel developer at Freescale
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