Re: [PATCH v3 4/4] mm: Remove managed_page_count spinlock

[Arun KS]

On 2018-11-08 15:44, Michal Hocko wrote:
> On Thu 08-11-18 15:33:06, Arun KS wrote:
> > On 2018-11-08 14:04, Michal Hocko wrote:
> > > On Thu 08-11-18 13:53:18, Arun KS wrote:
> > > > Now totalram_pages and managed_pages are atomic varibles. No need
> > > > of managed_page_count spinlock.
> > >
> > > As explained earlier. Please add a motivation here. Feel free to reuse
> > > wording from
> > > http://lkml.kernel.org/r/20181107103630.GF2453@xxxxxxxxxxxxxx
> >
> > Sure. Will add in next spin.
>
> Andrew usually updates changelogs if you give him the full wording.
> I would wait few days before resubmitting, if that is needed at all.

mm: Remove managed_page_count spinlock

Now that totalram_pages and managed_pages are atomic varibles, no need
of managed_page_count spinlock. The lock had really a weak consistency
guarantee. It hasn't been used for anything but the update but no reader
actually cares about all the values being updated to be in sync.

Signed-off-by: Arun KS <arunks@xxxxxxxxxxxxxx>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>


> 0day will throw a lot of random configs which can reveal some 
> leftovers.

Yea. Fixed few of them during v3.

Regards,
Arun