Re: [PATCH v3 0/3] idle memory tracking

Vladimir Davydov
2015-04-29T07:58:53Z

Hi Minchan,

Thank you for taking a look at this patch set.

On Wed, Apr 29, 2015 at 12:57:22PM +0900, Minchan Kim wrote:
> On Tue, Apr 28, 2015 at 03:24:39PM +0300, Vladimir Davydov wrote:
> > * /proc/kpageidle. For each page this file contains a 64-bit number, which
> > equals 1 if the page is idle or 0 otherwise, indexed by PFN. A page is
>
> Why do we need 64bit per page to indicate just idle or not?

I don't think we need this, actually. I made this file 64 bit per page
only to conform to other /proc/kpage* files. Currently, I can't think of
any potential use for residual 63 bits, so personally I'm fine with 1
bit per page. If nobody comes with an idea about how > 1 bits could be
used, I'll switch /proc/kpageidle to a bitmask in the next iteration.

Thanks,
Vladimir