Re: Userspace cycle counting for loongson?

[fxzhang <fxzhang@ict.ac.cn>]

Arnaud Patard (Rtp) 写道:
> Laurent GUERBY <laurent@guerby.net> writes:
>
>   
> > Hi,
> >     
>
> Hi,
>
>   
> > I'd like to time some low level code, is there a way
> > to count cycles in userspace for loongson processors
> > running debian lenny?
> >     
>
> You can try using the mips instruction rdhwr to get the cycle counter. I
> didn't tested it but I think it should work.
>   
As far as I know, there is still no rdhwr instruction in LS2E/2F, but 
you can use mfc0/dmfc0 to read the 'count' cp0 register.
> I would have said oprofile too but unfortunately, it needs some special
> care on kernel side before it can be used.
>
> Arnaud
>
>
>