On 2021/3/15 15:52, Arnd Bergmann wrote:
On Mon, Mar 15, 2021 at 6:54 AM Jie Deng <jie.deng@xxxxxxxxx> wrote:
On 2021/3/15 11:13, Jason Wang wrote:
On 2021/3/15 9:14 上午, Jie Deng wrote:
On 2021/3/12 16:58, Arnd Bergmann wrote:
Then do you think it is necessary to mark the virtio bufs with
____cacheline_aligned ?
I think so, yes.
I haven't seen any virtio interface being marked yet. If this is a
problem, I believe it should be common for all virtio devices, right ?
Yes, but it's not a problem if the buffers are allocated separately
because kmalloc provinces a cachelinen aligned buffer on architectures
that need it.
It's only a problem here because there is a single allocation for three
objects that have different ownership states during the DMA (device
owned to-device, cpu-owned, device owned to-cpu).
Arnd
I'm not sure if this will actually cause a problem. But I'm OK to mark
the items
in struct virtio_i2c_req with ____cacheline_aligned to avoid potential
problem
as you said.
Thank you.
