From: Jason Gunthorpe <jgg@nvidia.com>
To: Tejun Heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>,
Alistair Popple <apopple@nvidia.com>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, jhubbard@nvidia.com,
tjmercier@google.com, hannes@cmpxchg.org, surenb@google.com,
mkoutny@suse.com, daniel@ffwll.ch,
"Daniel P . Berrange" <berrange@redhat.com>,
Alex Williamson <alex.williamson@redhat.com>,
Zefan Li <lizefan.x@bytedance.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 14/19] mm: Introduce a cgroup for pinned memory
Date: Tue, 7 Feb 2023 08:19:57 -0400 [thread overview]
Message-ID: <Y+JB7VQX+Ypof4j6@nvidia.com> (raw)
In-Reply-To: <Y+GcJQRhvjqFaaSp@mtj.duckdns.org>
On Mon, Feb 06, 2023 at 02:32:37PM -1000, Tejun Heo wrote:
> Hello,
>
> On Mon, Feb 06, 2023 at 07:40:55PM -0400, Jason Gunthorpe wrote:
> > (a) kind of destroys the point of this as a sandboxing tool
> >
> > It is not so harmful to use memory that someone else has been charged
> > with allocating.
> >
> > But it is harmful to pin memory if someone else is charged for the
> > pin. It means it is unpredictable how much memory a sandbox can
> > actually lock down.
> >
> > Plus we have the double accounting problem, if 1000 processes in
> > different cgroups open the tmpfs and all pin the memory then cgroup A
> > will be charged 1000x for the memory and hit its limit, possibly
> > creating a DOS from less priv to more priv
>
> Let's hear what memcg people think about it. I'm not a fan of disassociating
> the ownership and locker of the same page but it is true that actively
> increasing locked consumption on a remote cgroup is awkward too.
The main purpose of all this is to support libvirt, so they need to
support (a) too.
(b) is what we have now and most closely emulates the way the RLIMIT
works.
Jason
WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Yosry Ahmed <yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
Alistair Popple <apopple-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
jhubbard-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org,
tjmercier-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org,
surenb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
mkoutny-IBi9RG/b67k@public.gmane.org,
daniel-/w4YWyX8dFk@public.gmane.org,
"Daniel P . Berrange"
<berrange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Alex Williamson
<alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Zefan Li <lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
Subject: Re: [PATCH 14/19] mm: Introduce a cgroup for pinned memory
Date: Tue, 7 Feb 2023 08:19:57 -0400 [thread overview]
Message-ID: <Y+JB7VQX+Ypof4j6@nvidia.com> (raw)
In-Reply-To: <Y+GcJQRhvjqFaaSp-qYNAdHglDFBN0TnZuCh8vA@public.gmane.org>
On Mon, Feb 06, 2023 at 02:32:37PM -1000, Tejun Heo wrote:
> Hello,
>
> On Mon, Feb 06, 2023 at 07:40:55PM -0400, Jason Gunthorpe wrote:
> > (a) kind of destroys the point of this as a sandboxing tool
> >
> > It is not so harmful to use memory that someone else has been charged
> > with allocating.
> >
> > But it is harmful to pin memory if someone else is charged for the
> > pin. It means it is unpredictable how much memory a sandbox can
> > actually lock down.
> >
> > Plus we have the double accounting problem, if 1000 processes in
> > different cgroups open the tmpfs and all pin the memory then cgroup A
> > will be charged 1000x for the memory and hit its limit, possibly
> > creating a DOS from less priv to more priv
>
> Let's hear what memcg people think about it. I'm not a fan of disassociating
> the ownership and locker of the same page but it is true that actively
> increasing locked consumption on a remote cgroup is awkward too.
The main purpose of all this is to support libvirt, so they need to
support (a) too.
(b) is what we have now and most closely emulates the way the RLIMIT
works.
Jason
next prev parent reply other threads:[~2023-02-07 12:20 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-06 7:47 [PATCH 00/19] mm: Introduce a cgroup to limit the amount of locked and pinned memory Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 01/19] mm: Introduce vm_account Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 02/19] drivers/vhost: Convert to use vm_account Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 03/19] drivers/vdpa: Convert vdpa to use the new vm_structure Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 04/19] infiniband/umem: Convert to use vm_account Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 05/19] RMDA/siw: " Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-12 17:32 ` Bernard Metzler
2023-02-06 7:47 ` [PATCH 06/19] RDMA/usnic: convert " Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 07/19] vfio/type1: Charge pinned pages to pinned_vm instead of locked_vm Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 08/19] vfio/spapr_tce: Convert accounting to pinned_vm Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 09/19] io_uring: convert to use vm_account Alistair Popple
2023-02-06 15:29 ` Jens Axboe
2023-02-06 15:29 ` Jens Axboe
2023-02-07 1:03 ` Alistair Popple
2023-02-07 1:03 ` Alistair Popple
2023-02-07 14:28 ` Jens Axboe
2023-02-07 14:55 ` Jason Gunthorpe
2023-02-07 14:55 ` Jason Gunthorpe
2023-02-07 17:05 ` Jens Axboe
2023-02-07 17:05 ` Jens Axboe
2023-02-13 11:30 ` Alistair Popple
2023-02-13 11:30 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 10/19] net: skb: Switch to using vm_account Alistair Popple
2023-02-06 7:47 ` [PATCH 11/19] xdp: convert to use vm_account Alistair Popple
2023-02-06 7:47 ` [PATCH 12/19] kvm/book3s_64_vio: Convert account_locked_vm() to vm_account_pinned() Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 13/19] fpga: dfl: afu: convert to use vm_account Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 14/19] mm: Introduce a cgroup for pinned memory Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 21:01 ` Yosry Ahmed
2023-02-06 21:01 ` Yosry Ahmed
2023-02-06 21:14 ` Tejun Heo
2023-02-06 21:14 ` Tejun Heo
2023-02-06 22:32 ` Yosry Ahmed
2023-02-06 22:32 ` Yosry Ahmed
2023-02-06 22:36 ` Tejun Heo
2023-02-06 22:39 ` Yosry Ahmed
2023-02-06 22:39 ` Yosry Ahmed
2023-02-06 23:25 ` Tejun Heo
2023-02-06 23:25 ` Tejun Heo
2023-02-06 23:34 ` Yosry Ahmed
2023-02-06 23:34 ` Yosry Ahmed
2023-02-06 23:40 ` Jason Gunthorpe
2023-02-06 23:40 ` Jason Gunthorpe
2023-02-07 0:32 ` Tejun Heo
2023-02-07 0:32 ` Tejun Heo
2023-02-07 12:19 ` Jason Gunthorpe [this message]
2023-02-07 12:19 ` Jason Gunthorpe
2023-02-15 19:00 ` Michal Hocko
2023-02-15 19:00 ` Michal Hocko
2023-02-15 19:07 ` Jason Gunthorpe
2023-02-15 19:07 ` Jason Gunthorpe
2023-02-16 8:04 ` Michal Hocko
2023-02-16 8:04 ` Michal Hocko
2023-02-16 12:45 ` Jason Gunthorpe
2023-02-16 12:45 ` Jason Gunthorpe
2023-02-21 16:51 ` Tejun Heo
2023-02-21 16:51 ` Tejun Heo
2023-02-21 17:25 ` Jason Gunthorpe
2023-02-21 17:29 ` Tejun Heo
2023-02-21 17:29 ` Tejun Heo
2023-02-21 17:51 ` Jason Gunthorpe
2023-02-21 17:51 ` Jason Gunthorpe
2023-02-21 18:07 ` Tejun Heo
2023-02-21 18:07 ` Tejun Heo
2023-02-21 19:26 ` Jason Gunthorpe
2023-02-21 19:26 ` Jason Gunthorpe
2023-02-21 19:45 ` Tejun Heo
2023-02-21 19:45 ` Tejun Heo
2023-02-21 19:49 ` Tejun Heo
2023-02-21 19:49 ` Tejun Heo
2023-02-21 19:57 ` Jason Gunthorpe
2023-02-22 11:38 ` Alistair Popple
2023-02-22 11:38 ` Alistair Popple
2023-02-22 12:57 ` Jason Gunthorpe
2023-02-22 12:57 ` Jason Gunthorpe
2023-02-22 22:59 ` Alistair Popple
2023-02-22 22:59 ` Alistair Popple
2023-02-23 0:05 ` Christoph Hellwig
2023-02-23 0:35 ` Alistair Popple
2023-02-23 0:35 ` Alistair Popple
2023-02-23 1:53 ` Jason Gunthorpe
2023-02-23 1:53 ` Jason Gunthorpe
2023-02-23 9:12 ` Daniel P. Berrangé
2023-02-23 17:31 ` Jason Gunthorpe
2023-02-23 17:31 ` Jason Gunthorpe
2023-02-23 17:18 ` T.J. Mercier
2023-02-23 17:28 ` Jason Gunthorpe
2023-02-23 17:28 ` Jason Gunthorpe
2023-02-23 18:03 ` Yosry Ahmed
2023-02-23 18:10 ` Jason Gunthorpe
2023-02-23 18:10 ` Jason Gunthorpe
2023-02-23 18:14 ` Yosry Ahmed
2023-02-23 18:14 ` Yosry Ahmed
2023-02-23 18:15 ` Tejun Heo
2023-02-23 18:17 ` Jason Gunthorpe
2023-02-23 18:17 ` Jason Gunthorpe
2023-02-23 18:22 ` Tejun Heo
2023-02-23 18:22 ` Tejun Heo
2023-02-07 1:00 ` Waiman Long
2023-02-07 1:00 ` Waiman Long
2023-02-07 1:03 ` Tejun Heo
2023-02-07 1:50 ` Alistair Popple
2023-02-07 1:50 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 15/19] mm/util: Extend vm_account to charge pages against the pin cgroup Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 16/19] mm/util: Refactor account_locked_vm Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 17/19] mm: Convert mmap and mlock to use account_locked_vm Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 7:47 ` [PATCH 18/19] mm/mmap: Charge locked memory to pins cgroup Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-06 21:12 ` Yosry Ahmed
2023-02-06 7:47 ` [PATCH 19/19] selftests/vm: Add pins-cgroup selftest for mlock/mmap Alistair Popple
2023-02-06 7:47 ` Alistair Popple
2023-02-16 11:01 ` [PATCH 00/19] mm: Introduce a cgroup to limit the amount of locked and pinned memory David Hildenbrand
2023-02-16 11:01 ` David Hildenbrand
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