Messages in this thread | | | Date | Fri, 30 May 2014 19:02:12 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v3 2/2] ARM : change fixmap mapping region to support 32 CPUs |
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On Fri, May 30, 2014 at 04:33:46PM +0100, Rob Herring wrote: > On Tue, Apr 15, 2014 at 6:06 AM, Liu Hua <sdu.liu@huawei.com> wrote: > > In 32-bit ARM systems, the fixmap mapping region can support > > no more than 14 CPUs(total: 896k; one CPU: 64K). And we can > > configure NR_CPUS up to 32. So there is a mismatch. > > > > This patch moves fixmapping region downwards to region > > 0xffc00000-0xffe00000. Then the fixmap mapping region can > > support up to 32 CPUs > > Ugg, this series breaks using fixmap for anything other than kmap > since 32 cpus requires all 2MB of the region and nothing is left. > There's work in flight to support early_ioremap, early console, and RO > text patching which all use the fixmap region. > > There's a couple of options to solve this: > > - Only support up to 16 cpus. It could be anywhere between 17-31, but > that seems somewhat unlikely. Are we really ever going to see 32-bit > 32 core systems?
I'd be fine with restricting the limit to 16 CPUs.
Will
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