On 12-Dec-17 7:34 AM, Tan, Jianfeng wrote:
Hi Anatoly,
-----Original Message-----
From: Burakov, Anatoly
Sent: Monday, December 11, 2017 6:00 PM
To: Tan, Jianfeng; dev@dpdk.org
Cc: Richardson, Bruce; Ananyev, Konstantin; tho...@monjalon.net
Subject: Re: [PATCH 0/3] generic channel for multi-process communication
On 30-Nov-17 6:44 PM, Jianfeng Tan wrote:
This patchset adds a generic channel for multi-process (primary/secondary)
communication.
Patch 1: addess the purpose and howto;
Patch 2: add a syncrhonous way for those messages which need a response
immediately.
Patch 3: Rework vfio to use this generic communication channel.
Hi Jianfeng,
Just a general comment: I am assuming this has the limitation of
"everything happens through primary process's involvement". This will
work for VFIO, as secondary always needs to ask the primary before doing
anything, but it doesn't address other issues that could have been
addressed with IPC.
For example, if a primary process would've hotplugged a device, it can't
notify all secondary processes about this; rather, it has to wait until
secondary processes ask for this info.
No need to wait the secondary to pull such info.
It can work like this:
(1) Register a hotplug callback for each process at initialization;
(2) Whenever a process wants to hotplug a device, it will broadcast the info,
by broadcast, I mean:
- if plugin happens at the primary, the primary will tell all of the
secondary processes;
- if plugin happens at one secondary, it will firstly tell the primary, and
the primary will broadcast it to all the secondary process.
Neither can it do anything if
secondary requests a primary to do something, and notify other secondary
processes about it (i.e. if secondary wants to hotplug a device, but
there are other secondaries also running). It would be great to have a
standard way of doing things like this in future revisions of our IPC.
Please review above thing; If you are OK with that, I'll include this in the
next version.
Thanks,
Jianfeng
--
Thanks,
Anatoly
Yes, that would work, my bad. However i don't think we necessarily need
it right now. This can go in a separate patch. I was rather looking at
other, future potential use cases, hotplug was just an example.
--
Thanks,
Anatoly
