From: Yosry Ahmed <yosryahmed@google.com>
To: Tejun Heo <tj@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, jgg@nvidia.com,
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: Mon, 6 Feb 2023 14:32:10 -0800 [thread overview]
Message-ID: <CAJD7tkb_Cr7rTTpKc1VBpS8h=n3Hu+nGiV8dkLH-NdC1bSG9mg@mail.gmail.com> (raw)
In-Reply-To: <Y+Fttp1ozejoSQzl@slm.duckdns.org>
On Mon, Feb 6, 2023 at 1:14 PM Tejun Heo <tj@kernel.org> wrote:
>
> On Mon, Feb 06, 2023 at 06:47:51PM +1100, Alistair Popple wrote:
> > If too much memory in a system is pinned or locked it can lead to
> > problems such as performance degradation or in the worst case
> > out-of-memory errors as such memory cannot be moved or paged out.
> >
> > In order to prevent users without CAP_IPC_LOCK from causing these
> > issues the amount of memory that can be pinned is typically limited by
> > RLIMIT_MEMLOCK. However this is inflexible as limits can't be shared
> > between tasks and the enforcement of these limits is inconsistent
> > between in-kernel users of pinned memory such as mlock() and device
> > drivers which may also pin pages with pin_user_pages().
> >
> > To allow for a single limit to be set introduce a cgroup controller
> > which can be used to limit the number of pages being pinned by all
> > tasks in the cgroup.
>
> As I wrote before, I think this might fit better as a part of memcg than as
> its own controller.
I guess it boils down to which we want:
(a) Limit the amount of memory processes in a cgroup can be pinned/locked.
(b) Limit the amount of memory charged to a cgroup that can be pinned/locked.
The proposal is doing (a), I suppose if this was part of memcg it
would be (b), right?
I am not saying it should be one or the other, I am just making sure
my understanding is clear.
>
> Thanks.
>
> --
> tejun
WARNING: multiple messages have this Message-ID (diff)
From: Yosry Ahmed <yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: 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,
jgg-DDmLM1+adcrQT0dZR+AlfA@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: Mon, 6 Feb 2023 14:32:10 -0800 [thread overview]
Message-ID: <CAJD7tkb_Cr7rTTpKc1VBpS8h=n3Hu+nGiV8dkLH-NdC1bSG9mg@mail.gmail.com> (raw)
In-Reply-To: <Y+Fttp1ozejoSQzl-NiLfg/pYEd1N0TnZuCh8vA@public.gmane.org>
On Mon, Feb 6, 2023 at 1:14 PM Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
>
> On Mon, Feb 06, 2023 at 06:47:51PM +1100, Alistair Popple wrote:
> > If too much memory in a system is pinned or locked it can lead to
> > problems such as performance degradation or in the worst case
> > out-of-memory errors as such memory cannot be moved or paged out.
> >
> > In order to prevent users without CAP_IPC_LOCK from causing these
> > issues the amount of memory that can be pinned is typically limited by
> > RLIMIT_MEMLOCK. However this is inflexible as limits can't be shared
> > between tasks and the enforcement of these limits is inconsistent
> > between in-kernel users of pinned memory such as mlock() and device
> > drivers which may also pin pages with pin_user_pages().
> >
> > To allow for a single limit to be set introduce a cgroup controller
> > which can be used to limit the number of pages being pinned by all
> > tasks in the cgroup.
>
> As I wrote before, I think this might fit better as a part of memcg than as
> its own controller.
I guess it boils down to which we want:
(a) Limit the amount of memory processes in a cgroup can be pinned/locked.
(b) Limit the amount of memory charged to a cgroup that can be pinned/locked.
The proposal is doing (a), I suppose if this was part of memcg it
would be (b), right?
I am not saying it should be one or the other, I am just making sure
my understanding is clear.
>
> Thanks.
>
> --
> tejun
next prev parent reply other threads:[~2023-02-06 22:32 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 [this message]
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
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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