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From: Greg KH <gregkh@linuxfoundation.org>
To: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: netdev@vger.kernel.org, kernel-team@fb.com
Subject: Re: [RFC PATCH v2 10/21] netgpu: add network/gpu/host dma module
Date: Tue, 28 Jul 2020 18:26:08 +0200	[thread overview]
Message-ID: <20200728162608.GA4181352@kroah.com> (raw)
In-Reply-To: <20200727224444.2987641-11-jonathan.lemon@gmail.com>

On Mon, Jul 27, 2020 at 03:44:33PM -0700, Jonathan Lemon wrote:
> From: Jonathan Lemon <bsd@fb.com>
> 
> Netgpu provides a data path for zero-copy sends and receives
> without having the host CPU touch the data.  Protocol processing
> is done on the host CPU, while data is DMA'd to and from DMA
> mapped memory areas.  The initial code provides transfers between
> (mlx5 / host memory) and (mlx5 / nvidia GPU memory).
> 
> The use case for this module are GPUs used for machine learning,
> which are located near the NICs, and have a high bandwidth PCI
> connection between the GPU/NIC.

Do we have such a GPU driver in the kernel today?  We can't add new
apis/interfaces for no in-kernel users, as you well know.

There's lots of crazyness in this patch, but this is just really odd:

> +#if IS_MODULE(CONFIG_NETGPU)
> +#define MAYBE_EXPORT_SYMBOL(s)
> +#else
> +#define MAYBE_EXPORT_SYMBOL(s)	EXPORT_SYMBOL(s)
> +#endif

Why is that needed at all?  Why does no one else in the kernel need such
a thing?

And why EXPORT_SYMBOL() and not EXPORT_SYMBOL_GPL() (I have to ask).

thanks,

greg k-h

  reply	other threads:[~2020-07-28 16:26 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 [this message]
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
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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