RE: [PATCH v2 6/8] x86: Add hardware prefetch control support for x86

From: tarumizu.kohei@xxxxxxxxxxx
Date: Fri Mar 18 2022 - 02:47:28 EST


> > +static int broadwell_write_pfreg(enum pfctl_attr pattr, unsigned int cpu,
> > + unsigned int level, u64 val)
> > +{
> > + int ret;
> > + u64 reg;
> > +
> > + ret = rdmsrl_on_cpu(cpu, MSR_MISC_FEATURE_CONTROL, &reg);
> > + if (ret)
> > + return ret;
> > +
> > + ret = broadwell_modify_pfreg(pattr, &reg, level, val);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = wrmsrl_on_cpu(cpu, MSR_MISC_FEATURE_CONTROL, reg);
> > + if (ret)
> > + return ret;
> > +
> > + return 0;
> > +}
>
> This needs to integrate _somehow_ with the pseudo_lock.c code. Right now, I
> suspect that code would just overwrite any MSR changes made by this code.

I lacked consideration for pseudo_lock.c code. I try to integration
with that code.