Re: [PATCH 2/5] cgroup/cpuset: Add new cpus.partition type with no load balancing

[Waiman Long]

On 6/16/21 4:47 PM, Tejun Heo wrote:
> Hello,
>
> Generally looks fine to me.
>
> On Thu, Jun 03, 2021 at 05:24:13PM -0400, Waiman Long wrote:
> > @@ -1984,12 +1987,31 @@ static int update_prstate(struct cpuset *cs, int val)
> >   			goto out;
> >   
> >   		err = update_parent_subparts_cpumask(cs, partcmd_enable,
> > -						     NULL, &tmp);
> > +						     NULL, &tmpmask);
> > +
> >   		if (err) {
> >   			update_flag(CS_CPU_EXCLUSIVE, cs, 0);
> >   			goto out;
> > +		} else if (new_prs == PRS_ENABLED_NOLB) {
> > +			/*
> > +			 * Disable the load balance flag should not return an
>                                   ^ing
>
> and "else if" after "if (err) goto out" block is weird. The two conditions
> don't need to be tied together.

Yes, the else part is redundant in this case. Will remove it.


> > @@ -2518,6 +2547,9 @@ static int sched_partition_show(struct seq_file *seq, void *v)
> >   	case PRS_ENABLED:
> >   		seq_puts(seq, "root\n");
> >   		break;
> > +	case PRS_ENABLED_NOLB:
> > +		seq_puts(seq, "root-nolb\n");
> > +		break;
> >   	case PRS_DISABLED:
> >   		seq_puts(seq, "member\n");
> >   		break;
> > @@ -2544,6 +2576,8 @@ static ssize_t sched_partition_write(struct kernfs_open_file *of, char *buf,
> >   		val = PRS_ENABLED;
> >   	else if (!strcmp(buf, "member"))
> >   		val = PRS_DISABLED;
> > +	else if (!strcmp(buf, "root-nolb"))
> > +		val = PRS_ENABLED_NOLB;
> >   	else
> >   		return -EINVAL;
> I wonder whether there's a better name than "root-nolb" because nolb isn't
> the most readable and we are using space as the delimiter for other names.
> Would something like "isolated" work?

Right. "isolated" is a better name and it corresponds better with the 
isolcpus kernel command line option. Will change the name.

Thanks,
Longman