Re: [PATCH 2/5] x86/mbm: Intel Memory B/W Monitoring enumeration and init

[Vikas Shivappa]

On Wed, 24 Feb 2016, Thomas Gleixner wrote:

> On Wed, 10 Feb 2016, Vikas Shivappa wrote:ar
> > +static int intel_mbm_init(void)
> > +{
> > +	int ret = 0, array_size, maxid = cqm_max_rmid + 1;
> > +
> > +	mbm_socket_max = cpumask_weight(&cqm_cpumask);
>
> This should use the new topology_max_packages() function, so you can alloc
> your array correctly even if not all sockets are online/plugged yet.

Will fix. Thanks for pointing out.

> > +	array_size = sizeof(struct sample) * maxid * mbm_socket_max;
> > +	mbm_local = kmalloc(array_size, GFP_KERNEL);
> > +	if (!mbm_local) {
> > +		ret = -ENOMEM;
>
> return -ENOMEM is sufficient here.

Will fix

> > +		goto out;
> > +	}
> > +
> > +	mbm_total = kmalloc(array_size, GFP_KERNEL);
> > +	if (!mbm_total) {
> > +		kfree(mbm_local);
> > +		ret = -ENOMEM;
> > +	}
> > +out:
> > +
> > +	return ret;
> > +}
> > +
> >  	cqm_l3_scale = boot_cpu_data.x86_cache_occ_scale;
> > @@ -1384,14 +1520,34 @@ static int __init intel_cqm_init(void)
> >
> >  	__perf_cpu_notifier(intel_cqm_cpu_notifier);
>
> You really should register the notifier _AFTER_ registering the pmu. That
> needs to be fixed anyway, because the existing code leaks the notifier AND
> memory in case perf_pmu_register fails.

Correct, Will fix the notifier leak

Thanks,
Vikas

> Thanks,
>
> 	tglx