On 7 April 2016 at 11:56, Vijay Kilari <[email protected]> wrote: > On Thu, Apr 7, 2016 at 3:41 PM, Peter Maydell <[email protected]> > wrote: >> On 7 April 2016 at 10:58, <[email protected]> wrote: >>> From: Vijaya Kumar K <[email protected]> >>> >>> utils cannot read target cpu information to >>> fetch cpu information to implement cpu specific >>> features or erratas. For this parse /proc/cpuinfo >>> and fetch cpu information. >>> >>> For now this helper only fetches cpu information >>> for arm architectures. >> >> As I understand it /proc/cpuinfo is intended only for >> humans to read. Please don't write code to parse it; >> find a different way to get this information instead >> if you really need it.
> Also unlike x86 there is no cpuid.h where we can get cpu identification > information for arm64. I'm told there are kernel patches in progress to get this sort of information in a maintainable way to userspace, which are currently somewhat stalled due to lack of anybody who wants to consume it. If you have a use case then you should probably flag it up with the kernel devs. That said, I think we should probably hold off on this discussion until we have clearer benchmarking info that demonstrates that doing these prefetches really does make a significant difference. I would much prefer to have a single aarch64 routine that works for everybody, rather than a thunderx-only special case. thanks -- PMM
