netdev - Re: [PATCH net-next v10 02/14] net: page_pool: create hooks for custom page providers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 10 Jun 2024 20:32:16 +0100
From: Pavel Begunkov <asml.silence@...il.com>
To: Mina Almasry <almasrymina@...gle.com>,
 Christian König <christian.koenig@....com>
Cc: Jason Gunthorpe <jgg@...pe.ca>, David Wei <dw@...idwei.uk>,
 David Ahern <dsahern@...nel.org>, Christoph Hellwig <hch@...radead.org>,
 netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-doc@...r.kernel.org, linux-alpha@...r.kernel.org,
 linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org,
 sparclinux@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
 linux-arch@...r.kernel.org, bpf@...r.kernel.org,
 linux-kselftest@...r.kernel.org, linux-media@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, "David S. Miller" <davem@...emloft.net>,
 Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Donald Hunter <donald.hunter@...il.com>,
 Jonathan Corbet <corbet@....net>,
 Richard Henderson <richard.henderson@...aro.org>,
 Ivan Kokshaysky <ink@...assic.park.msu.ru>, Matt Turner
 <mattst88@...il.com>, Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
 "James E.J. Bottomley" <James.Bottomley@...senpartnership.com>,
 Helge Deller <deller@....de>, Andreas Larsson <andreas@...sler.com>,
 Jesper Dangaard Brouer <hawk@...nel.org>,
 Ilias Apalodimas <ilias.apalodimas@...aro.org>,
 Steven Rostedt <rostedt@...dmis.org>, Masami Hiramatsu
 <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
 Arnd Bergmann <arnd@...db.de>, Alexei Starovoitov <ast@...nel.org>,
 Daniel Borkmann <daniel@...earbox.net>, Andrii Nakryiko <andrii@...nel.org>,
 Martin KaFai Lau <martin.lau@...ux.dev>, Eduard Zingerman
 <eddyz87@...il.com>, Song Liu <song@...nel.org>,
 Yonghong Song <yonghong.song@...ux.dev>,
 John Fastabend <john.fastabend@...il.com>, KP Singh <kpsingh@...nel.org>,
 Stanislav Fomichev <sdf@...gle.com>, Hao Luo <haoluo@...gle.com>,
 Jiri Olsa <jolsa@...nel.org>, Steffen Klassert
 <steffen.klassert@...unet.com>, Herbert Xu <herbert@...dor.apana.org.au>,
 Willem de Bruijn <willemdebruijn.kernel@...il.com>,
 Shuah Khan <shuah@...nel.org>, Sumit Semwal <sumit.semwal@...aro.org>,
 Yunsheng Lin <linyunsheng@...wei.com>, Shailend Chand <shailend@...gle.com>,
 Harshitha Ramamurthy <hramamurthy@...gle.com>,
 Shakeel Butt <shakeel.butt@...ux.dev>, Jeroen de Borst
 <jeroendb@...gle.com>, Praveen Kaligineedi <pkaligineedi@...gle.com>
Subject: Re: [PATCH net-next v10 02/14] net: page_pool: create hooks for
 custom page providers

On 6/10/24 16:41, Mina Almasry wrote:
> On Mon, Jun 10, 2024 at 5:38 AM Christian König
> <christian.koenig@....com> wrote:
>>
>> Am 10.06.24 um 14:16 schrieb Jason Gunthorpe:
>>> On Mon, Jun 10, 2024 at 02:07:01AM +0100, Pavel Begunkov wrote:
>>>> On 6/10/24 01:37, David Wei wrote:
>>>>> On 2024-06-07 17:52, Jason Gunthorpe wrote:
>>>>>> IMHO it seems to compose poorly if you can only use the io_uring
>>>>>> lifecycle model with io_uring registered memory, and not with DMABUF
>>>>>> memory registered through Mina's mechanism.
>>>>> By this, do you mean io_uring must be exclusively used to use this
>>>>> feature?
>>>>>
>>>>> And you'd rather see the two decoupled, so userspace can register w/ say
>>>>> dmabuf then pass it to io_uring?
>>>> Personally, I have no clue what Jason means. You can just as
>>>> well say that it's poorly composable that write(2) to a disk
>>>> cannot post a completion into a XDP ring, or a netlink socket,
>>>> or io_uring's main completion queue, or name any other API.
>>> There is no reason you shouldn't be able to use your fast io_uring
>>> completion and lifecycle flow with DMABUF backed memory. Those are not
>>> widly different things and there is good reason they should work
>>> together.
>>
>> Well there is the fundamental problem that you can't use io_uring to
>> implement the semantics necessary for a dma_fence.
>>
>> That's why we had to reject the io_uring work on DMA-buf sharing from
>> Google a few years ago.
>>
> 
> Any chance someone can link me to this? io_uring, as far as my
> primitive understanding goes, is not yet very adopted at Google, and
> I'm curious what this effort is.
I'm curious as well, I don't remember it floating anywhere in mailing
lists. The only discussion I recall was about
DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, but it didn't get through only because
someone pushed for evenfds.

-- 
Pavel Begunkov