From: Andi Kleen <ak@linux.intel.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Mikael Pettersson <mikpelinux@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org
Subject: Re: [PATCH] mm: disable `vm.max_map_count' sysctl limit
Date: Mon, 27 Nov 2017 12:21:21 -0800 [thread overview]
Message-ID: <20171127202121.GB3070@tassilo.jf.intel.com> (raw)
In-Reply-To: <20171127195732.3hkfx57d3ytyccvp@dhcp22.suse.cz>
On Mon, Nov 27, 2017 at 08:57:32PM +0100, Michal Hocko wrote:
> On Mon 27-11-17 19:32:18, Michal Hocko wrote:
> > On Mon 27-11-17 09:25:16, Andi Kleen wrote:
> [...]
> > > The reason the limit was there originally because it allows a DoS
> > > attack against the kernel by filling all unswappable memory up with VMAs.
> >
> > We can reduce the effect by accounting vmas to memory cgroups.
>
> As it turned out we already do.
> vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC|SLAB_ACCOUNT);
That only helps if you have memory cgroups enabled. It would be a regression
to break the accounting on all the systems that don't.
-Andi
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next prev parent reply other threads:[~2017-11-27 20:21 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-26 16:09 [PATCH] mm: disable `vm.max_map_count' sysctl limit Mikael Pettersson
2017-11-27 10:12 ` Michal Hocko
2017-11-27 16:22 ` Matthew Wilcox
2017-11-27 19:28 ` Mikael Pettersson
2017-11-27 17:25 ` Andi Kleen
2017-11-27 18:32 ` Michal Hocko
2017-11-27 19:57 ` Michal Hocko
2017-11-27 20:21 ` Andi Kleen [this message]
2017-11-27 20:52 ` Michal Hocko
2017-11-27 19:36 ` Mikael Pettersson
2017-11-27 19:18 ` Mikael Pettersson
2017-11-27 19:52 ` Michal Hocko
2017-11-27 23:26 ` John Hubbard
2017-11-28 8:12 ` Michal Hocko
2017-11-29 5:14 ` John Hubbard
2017-11-29 8:32 ` Michal Hocko
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