From: Jason Gunthorpe <jgg@nvidia.com>
To: Alistair Popple <apopple@nvidia.com>
Cc: 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, netdev@vger.kernel.org,
linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com
Subject: Re: [RFC PATCH 10/19] net: skb: Switch to using vm_account
Date: Mon, 6 Feb 2023 09:14:02 -0400 [thread overview]
Message-ID: <Y+D9Gkuo1/l0Ty9W@nvidia.com> (raw)
In-Reply-To: <878rhbflcs.fsf@nvidia.com>
On Mon, Feb 06, 2023 at 03:36:49PM +1100, Alistair Popple wrote:
> >> But then I don't really know how RDS works, Santos?
> >>
> >> Regardless, maybe the vm_account should be stored in the
> >> rds_msg_zcopy_info ?
> >
> > On first glance that looks like a better spot. Thanks for the
> > idea.
>
> That works fine for RDS but not for skbuff.
I would definately put the RDS stuff like that..
> We still need a vm_account in the struct sock or somewhere else for
> that. For example in msg_zerocopy_realloc() we only have a struct
> ubuf_info_msgzc available. We can't add a struct vm_account field to
> that because ultimately it is stored in struct sk_buff->ck[] which
> is not large enough to contain ubuf_info_msgzc + vm_account.
Well, AFAICT this is using iov_iter to get the pages and in general
iov_iter - eg as used for O_DIRECT - doesn't charge anything.
If this does somehow allow a userspace to hold pin a page for a long
time then it is already technically wrong because it doesn't use
FOLL_LONGTERM.
Arguably FOLL_LONGTERM should be the key precondition to require
accounting.
So I wonder if it should just be deleted?
Jason
next prev parent reply other threads:[~2023-02-06 13:14 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-24 5:42 [RFC PATCH 00/19] mm: Introduce a cgroup to limit the amount of locked and pinned memory Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 01/19] mm: Introduce vm_account Alistair Popple
2023-01-24 6:29 ` Christoph Hellwig
2023-01-24 14:32 ` Jason Gunthorpe
2023-01-30 11:36 ` Alistair Popple
2023-01-31 14:00 ` David Hildenbrand
2023-01-24 5:42 ` [RFC PATCH 02/19] drivers/vhost: Convert to use vm_account Alistair Popple
2023-01-24 5:55 ` Michael S. Tsirkin
2023-01-30 10:43 ` Alistair Popple
2023-01-24 14:34 ` Jason Gunthorpe
2023-01-24 5:42 ` [RFC PATCH 03/19] drivers/vdpa: Convert vdpa to use the new vm_structure Alistair Popple
2023-01-24 14:35 ` Jason Gunthorpe
2023-01-24 5:42 ` [RFC PATCH 04/19] infiniband/umem: Convert to use vm_account Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 05/19] RMDA/siw: " Alistair Popple
2023-01-24 14:37 ` Jason Gunthorpe
2023-01-24 15:22 ` Bernard Metzler
2023-01-24 15:56 ` Bernard Metzler
2023-01-30 11:34 ` Alistair Popple
2023-01-30 13:27 ` Bernard Metzler
2023-01-24 5:42 ` [RFC PATCH 06/19] RDMA/usnic: convert " Alistair Popple
2023-01-24 14:41 ` Jason Gunthorpe
2023-01-30 11:10 ` Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 07/19] vfio/type1: Charge pinned pages to pinned_vm instead of locked_vm Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 08/19] vfio/spapr_tce: Convert accounting to pinned_vm Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 09/19] io_uring: convert to use vm_account Alistair Popple
2023-01-24 14:44 ` Jason Gunthorpe
2023-01-30 11:12 ` Alistair Popple
2023-01-30 13:21 ` Jason Gunthorpe
2023-01-24 5:42 ` [RFC PATCH 10/19] net: skb: Switch to using vm_account Alistair Popple
2023-01-24 14:51 ` Jason Gunthorpe
2023-01-30 11:17 ` Alistair Popple
2023-02-06 4:36 ` Alistair Popple
2023-02-06 13:14 ` Jason Gunthorpe [this message]
2023-01-24 5:42 ` [RFC PATCH 11/19] xdp: convert to use vm_account Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 12/19] kvm/book3s_64_vio: Convert account_locked_vm() to vm_account_pinned() Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 13/19] fpga: dfl: afu: convert to use vm_account Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 14/19] mm: Introduce a cgroup for pinned memory Alistair Popple
2023-01-27 21:44 ` Tejun Heo
2023-01-30 13:20 ` Jason Gunthorpe
2023-01-24 5:42 ` [RFC PATCH 15/19] mm/util: Extend vm_account to charge pages against the pin cgroup Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 16/19] mm/util: Refactor account_locked_vm Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 17/19] mm: Convert mmap and mlock to use account_locked_vm Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 18/19] mm/mmap: Charge locked memory to pins cgroup Alistair Popple
2023-01-24 5:42 ` [RFC PATCH 19/19] selftests/vm: Add pins-cgroup selftest for mlock/mmap Alistair Popple
2023-01-24 18:26 ` [RFC PATCH 00/19] mm: Introduce a cgroup to limit the amount of locked and pinned memory Yosry Ahmed
2023-01-31 0:54 ` Alistair Popple
2023-01-31 5:14 ` Yosry Ahmed
2023-01-31 11:22 ` Alistair Popple
2023-01-31 19:49 ` Yosry Ahmed
2023-01-24 20:12 ` Jason Gunthorpe
2023-01-31 13:57 ` David Hildenbrand
2023-01-31 14:03 ` Jason Gunthorpe
2023-01-31 14:06 ` David Hildenbrand
2023-01-31 14:10 ` Jason Gunthorpe
2023-01-31 14:15 ` David Hildenbrand
2023-01-31 14:21 ` Jason Gunthorpe
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