Re: [PATCH] proc: add percpu populated pages count to meminfo

From: Dennis Zhou
Date: Tue Aug 07 2018 - 11:03:34 EST


Hi Vlastimil,

On Tue, Aug 07, 2018 at 03:18:31PM +0200, Vlastimil Babka wrote:
>
> Documentation/filesystems/proc.txt should be updated as well
>

Will do.

> >
> > +/*
> > + * The number of populated pages in use by the allocator, protected by
> > + * pcpu_lock. This number is kept per a unit per chunk (i.e. when a page gets
> > + * allocated/deallocated, it is allocated/deallocated in all units of a chunk
> > + * and increments/decrements this count by 1).
> > + */
> > +static int pcpu_nr_populated;
>
> It better be unsigned long, to match others.
>

Yeah that makes sense. I've changed this for v2.

> > +/*
> > + * pcpu_nr_populated_pages - calculate total number of populated backing pages
> > + *
> > + * This reflects the number of pages populated to back the chunks.
> > + * Metadata is excluded in the number exposed in meminfo as the number of
> > + * backing pages scales with the number of cpus and can quickly outweigh the
> > + * memory used for metadata. It also keeps this calculation nice and simple.
> > + *
> > + * RETURNS:
> > + * Total number of populated backing pages in use by the allocator.
> > + */
> > +int pcpu_nr_populated_pages(void)
>
> Also unsigned long please.
>

Changed for v2.

Thanks,
Dennis