Re: [RFC] psi: Add additional PSI counters for each type of memory pressure

[Georgi Djakov]

On 10.11.21 18:14, Peter Zijlstra wrote:
> On Wed, Nov 10, 2021 at 07:36:37AM -0800, Georgi Djakov wrote:
> > @@ -21,7 +19,18 @@ enum psi_task_count {
> >   	 * don't have to special case any state tracking for it.
> >   	 */
> >   	NR_ONCPU,
> > -	NR_PSI_TASK_COUNTS = 4,
> > +	NR_BLK_CGROUP_THROTTLE,
> > +	NR_BIO,
> > +	NR_COMPACTION,
> > +	NR_THRASHING,
> > +	NR_CGROUP_RECLAIM_HIGH,
> > +	NR_CGROUP_RECLAIM_HIGH_SLEEP,
> > +	NR_CGROUP_TRY_CHARGE,
> > +	NR_DIRECT_COMPACTION,
> > +	NR_DIRECT_RECLAIM,
> > +	NR_READ_SWAPPAGE,
> > +	NR_KSWAPD,
> > +	NR_PSI_TASK_COUNTS = 16,
> >   };
> >   
>
> > @@ -51,9 +80,20 @@ enum psi_states {
> >   	PSI_MEM_FULL,
> >   	PSI_CPU_SOME,
> >   	PSI_CPU_FULL,
> > +	PSI_BLK_CGROUP_THROTTLE,
> > +	PSI_BIO,
> > +	PSI_COMPACTION,
> > +	PSI_THRASHING,
> > +	PSI_CGROUP_RECLAIM_HIGH,
> > +	PSI_CGROUP_RECLAIM_HIGH_SLEEP,
> > +	PSI_CGROUP_TRY_CHARGE,
> > +	PSI_DIRECT_COMPACTION,
> > +	PSI_DIRECT_RECLAIM,
> > +	PSI_READ_SWAPPAGE,
> > +	PSI_KSWAPD,
> >   	/* Only per-CPU, to weigh the CPU in the global average: */
> >   	PSI_NONIDLE,
> > -	NR_PSI_STATES = 7,
> > +	NR_PSI_STATES = 18,
> >   };
>
> Have you considered what this does to psi_group_cpu's size and layout
> and the impact thereof on performance?

Thanks, i will definitely add some numbers in case there are no other
major arguments against this RFC patch.

BR,
Georgi