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From: Michal Hocko <mhocko@kernel.org>
To: Chris Friesen <chris.friesen@windriver.com>
Cc: "cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
	linux-mm@kvack.org, Johannes Weiner <hannes@cmpxchg.org>,
	Vladimir Davydov <vdavydov.dev@gmail.com>
Subject: Re: per-NUMA memory limits in mem cgroup?
Date: Sun, 22 Apr 2018 06:46:48 -0600	[thread overview]
Message-ID: <20180422124648.GD17484@dhcp22.suse.cz> (raw)
In-Reply-To: <5ADA26AB.6080209@windriver.com>

On Fri 20-04-18 11:43:07, Chris Friesen wrote:
> Hi,
> 
> I'm aware of the ability to use the memory controller to limit how much
> memory a group of tasks can consume.
> 
> Is there any way to limit how much memory a group of tasks can consume *per
> NUMA node*?

Not really. We have all or nothing via cpusets but nothing really fine
grained for the amount of memory.

> The specific scenario I'm considering is that of a hypervisor host.  I have
> system management stuff running on the host that may need more than one
> core, and currently these host tasks might be affined to cores from multiple
> NUMA nodes.  I'd like to put a cap on how much memory the host tasks can
> allocate from each NUMA node in order to ensure that there is a guaranteed
> amount of memory available for VMs on each NUMA node.
> 
> Is this possible, or are the knobs just not there?

Not possible right now. What would be the policy when you reach the
limit on one node? Fallback to other nodes? What if those hit the limit
as well? OOM killer or an allocation failure?
-- 
Michal Hocko
SUSE Labs

  reply	other threads:[~2018-04-22 12:46 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-20 17:43 per-NUMA memory limits in mem cgroup? Chris Friesen
2018-04-22 12:46 ` Michal Hocko [this message]
2018-04-23 15:29   ` Chris Friesen
2018-04-24 13:27     ` Michal Hocko
2018-04-24 15:13       ` Chris Friesen
2018-04-24 15:23         ` Michal Hocko

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