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From: Jonathan Lemon <jonathan.lemon@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: netdev@vger.kernel.org, kernel-team@fb.com
Subject: Re: [RFC PATCH v2 11/21] core/skbuff: add page recycling logic for netgpu pages
Date: Tue, 28 Jul 2020 11:00:40 -0700	[thread overview]
Message-ID: <20200728180040.az3xgwzmuz6grv32@bsd-mbp.dhcp.thefacebook.com> (raw)
In-Reply-To: <20200728162825.GC4181352@kroah.com>

On Tue, Jul 28, 2020 at 06:28:25PM +0200, Greg KH wrote:
> On Mon, Jul 27, 2020 at 03:44:34PM -0700, Jonathan Lemon wrote:
> > From: Jonathan Lemon <bsd@fb.com>
> > 
> > netgpu pages will always have a refcount of at least one (held by
> > the netgpu module).  If the skb is marked as containing netgpu ZC
> > pages, recycle them back to netgpu.
> 
> What???

Yes, this is page refcount elevation.  ZONE_DEVICE pages do this also,
which is hidden in put_devmap_managed_page().  I would really like to
find a generic solution for this, as it has come up in other cases as
well (page recycling for page_pool, for example).  Some way to say "this
page is different", and a separate routine to release refcounts.

Can we have a discussion on this possibility?
-- 
Jonathan

  reply	other threads:[~2020-07-28 18:00 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-27 22:44 [RFC PATCH v2 00/21] netgpu: networking between NIC and GPU/CPU Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 01/21] linux/log2.h: enclose macro arg in parens Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 02/21] mm/memory_hotplug: add {add|release}_memory_pages Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 03/21] mm: Allow DMA mapping of pages which are not online Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 04/21] kernel/user: export free_uid Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 05/21] uapi/misc: add shqueue.h for shared queues Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 06/21] include: add netgpu UAPI and kernel definitions Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 07/21] netdevice: add SETUP_NETGPU to the netdev_bpf structure Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 08/21] skbuff: add a zc_netgpu bitflag Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 09/21] core/skbuff: use skb_zdata for testing whether skb is zerocopy Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 10/21] netgpu: add network/gpu/host dma module Jonathan Lemon
2020-07-28 16:26   ` Greg KH
2020-07-28 17:41     ` Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 11/21] core/skbuff: add page recycling logic for netgpu pages Jonathan Lemon
2020-07-28 16:28   ` Greg KH
2020-07-28 18:00     ` Jonathan Lemon [this message]
2020-07-28 18:26       ` Greg KH
2020-07-27 22:44 ` [RFC PATCH v2 12/21] lib: have __zerocopy_sg_from_iter get netgpu pages for a sk Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 13/21] net/tcp: Pad TCP options out to a fixed size for netgpu Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 14/21] net/tcp: add netgpu ioctl setting up zero copy RX queues Jonathan Lemon
2020-07-28  2:16   ` Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 15/21] net/tcp: add MSG_NETDMA flag for sendmsg() Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 16/21] mlx5: remove the umem parameter from mlx5e_open_channel Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 17/21] mlx5e: add header split ability Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 18/21] mlx5e: add netgpu entries to mlx5 structures Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 19/21] mlx5e: add the netgpu driver functions Jonathan Lemon
2020-07-28 16:27   ` Greg KH
2020-07-27 22:44 ` [RFC PATCH v2 20/21] mlx5e: hook up the netgpu functions Jonathan Lemon
2020-07-27 22:44 ` [RFC PATCH v2 21/21] netgpu/nvidia: add Nvidia plugin for netgpu Jonathan Lemon
2020-07-28 16:31   ` Greg KH
2020-07-28 17:18     ` Chris Mason
2020-07-28 17:27       ` Christoph Hellwig
2020-07-28 18:47         ` Chris Mason
2020-07-28 19:55 ` [RFC PATCH v2 00/21] netgpu: networking between NIC and GPU/CPU Stephen Hemminger
2020-07-28 20:43   ` Jonathan Lemon

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