Re: [PATCH] mm: add config option to select the initial overcommit mode

From: Michal Hocko
Date: Fri May 13 2016 - 10:01:37 EST


On Fri 13-05-16 14:15:35, Mason wrote:
> On 13/05/2016 13:44, Michal Hocko wrote:
>
> > Anyway, this is my laptop where I do not run anything really special
> > (xfce, browser, few consoles, git, mutt):
> > $ grep Commit /proc/meminfo
> > CommitLimit: 3497288 kB
> > Committed_AS: 3560804 kB
> >
> > I am running with the default overcommit setup so I do not care about
> > the limit but the Committed_AS will tell you how much is actually
> > committed. I am definitelly not out of memory:
> > $ free
> > total used free shared buff/cache available
> > Mem: 3922584 1724120 217336 105264 1981128 2036164
> > Swap: 1535996 386364 1149632
>
> I see. Thanks for the data point.
>
> I had a different type of system in mind.
> 256 to 512 MB of RAM, no swap.
> Perhaps Sebastian's choice could be made to depend on CONFIG_EMBEDDED,
> rather than CONFIG_EXPERT?

Even if the overcommit behavior is different on those systems the
primary question hasn't been answered yet. Why cannot this be done from
the userspace? In other words what wouldn't work properly?

--
Michal Hocko
SUSE Labs