From: Stanislav Fomichev <stfomichev@gmail.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mina Almasry <almasrymina@google.com>,
netdev@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
Pavel Begunkov <asml.silence@gmail.com>,
Willem de Bruijn <willemb@google.com>,
Kaiyuan Zhang <kaiyuanz@google.com>,
Samiullah Khawaja <skhawaja@google.com>,
linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
Ilias Apalodimas <ilias.apalodimas@linaro.org>
Subject: Re: [PATCH net-next v2 4/5] page_pool: disable sync for cpu for dmabuf memory provider
Date: Fri, 8 Nov 2024 07:58:22 -0800 [thread overview]
Message-ID: <Zy41HkR5dDmjVJwl@mini-arch> (raw)
In-Reply-To: <20241108141812.GL35848@ziepe.ca>
On 11/08, Jason Gunthorpe wrote:
> On Thu, Nov 07, 2024 at 09:23:08PM +0000, Mina Almasry wrote:
> > dmabuf dma-addresses should not be dma_sync'd for CPU/device. Typically
> > its the driver responsibility to dma_sync for CPU, but the driver should
> > not dma_sync for CPU if the netmem is actually coming from a dmabuf
> > memory provider.
>
> This is not completely true, it is not *all* dmabuf, just the parts of
> the dmabuf that are actually MMIO.
>
> If you do this you may want to block accepting dmabufs that have CPU
> pages inside them.
We still want udmabufs to work, so probably need some new helper to test
whether a particular netmem is backed by the cpu memory?
next prev parent reply other threads:[~2024-11-08 15:58 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-07 21:23 [PATCH net-next v2 0/5] devmem TCP fixes Mina Almasry
2024-11-07 21:23 ` [PATCH net-next v2 1/5] net: page_pool: rename page_pool_alloc_netmem to *_netmems Mina Almasry
2024-11-08 15:53 ` Stanislav Fomichev
2024-11-07 21:23 ` [PATCH net-next v2 2/5] net: page_pool: create page_pool_alloc_netmem Mina Almasry
2024-11-08 15:53 ` Stanislav Fomichev
2024-11-07 21:23 ` [PATCH net-next v2 3/5] page_pool: Set `dma_sync` to false for devmem memory provider Mina Almasry
2024-11-08 15:53 ` Stanislav Fomichev
2024-11-08 16:34 ` Pavel Begunkov
2024-11-12 2:34 ` Jakub Kicinski
2024-11-07 21:23 ` [PATCH net-next v2 4/5] page_pool: disable sync for cpu for dmabuf " Mina Almasry
2024-11-08 14:18 ` Jason Gunthorpe
2024-11-08 15:58 ` Stanislav Fomichev [this message]
2024-11-08 16:39 ` Pavel Begunkov
2024-11-08 19:01 ` Mina Almasry
2024-11-15 1:59 ` Jason Gunthorpe
2024-11-22 22:10 ` Samiullah Khawaja
2024-11-24 2:33 ` Jakub Kicinski
2024-11-07 21:23 ` [PATCH net-next v2 5/5] netmem: add netmem_prefetch Mina Almasry
2024-11-08 2:56 ` kernel test robot
2024-11-08 3:29 ` kernel test robot
2024-11-08 4:21 ` kernel test robot
2024-11-08 15:55 ` Stanislav Fomichev
2024-11-12 2:35 ` Jakub Kicinski
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