From: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>
To: Neil Horman <nhorman@tuxdriver.com>,
Thomas Monjalon <thomas@monjalon.net>
Cc: "dev@dpdk.org" <dev@dpdk.org>, Matan Azrad <matan@mellanox.com>,
"Richardson, Bruce" <bruce.richardson@intel.com>,
Gaetan Rivet <gaetan.rivet@6wind.com>,
"Wu, Jingjing" <jingjing.wu@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2 2/6] ethdev: add port ownership
Date: Sat, 20 Jan 2018 12:54:18 +0000 [thread overview]
Message-ID: <2601191342CEEE43887BDE71AB97725886281227@irsmsx105.ger.corp.intel.com> (raw)
In-Reply-To: <20180119194739.GF9519@hmswarspite.think-freely.org>
Hi Neil,
> ----- Message-----
> From: Neil Horman [mailto:nhorman@tuxdriver.com]
> Sent: Friday, January 19, 2018 7:48 PM
> To: Thomas Monjalon <thomas@monjalon.net>
> Cc: dev@dpdk.org; Matan Azrad <matan@mellanox.com>; Richardson, Bruce <bruce.richardson@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Gaetan Rivet <gaetan.rivet@6wind.com>; Wu, Jingjing <jingjing.wu@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v2 2/6] ethdev: add port ownership
>
> On Fri, Jan 19, 2018 at 07:12:36PM +0100, Thomas Monjalon wrote:
> > 19/01/2018 18:43, Neil Horman:
> > > On Fri, Jan 19, 2018 at 06:17:51PM +0100, Thomas Monjalon wrote:
> > > > 19/01/2018 16:27, Neil Horman:
> > > > > On Fri, Jan 19, 2018 at 03:13:47PM +0100, Thomas Monjalon wrote:
> > > > > > 19/01/2018 14:30, Neil Horman:
> > > > > > > So it seems like the real point of contention that we need to settle here is,
> > > > > > > what codifies an 'owner'. Must it be a specific execution context, or can we
> > > > > > > define any arbitrary section of code as being an owner? I would agrue against
> > > > > > > the latter.
> > > > > >
> > > > > > This is the first thing explained in the cover letter:
> > > > > > "2. The port usage synchronization will be managed by the port owner."
> > > > > > There is no intent to manage the threads synchronization for a given port.
> > > > > > It is the responsibility of the owner (a code object) to configure its
> > > > > > port via only one thread.
> > > > > > It is consistent with not trying to manage threads synchronization
> > > > > > for Rx/Tx on a given queue.
> > > > > >
> > > > > >
> > > > > Yes, in his cover letter, and I contend that notion is an invalid design point.
> > > > > By codifying an area of code as an 'owner', rather than an execution context,
> > > > > you're defining the notion of heirarchy, not ownership. That is to say,
> > > > > you want to codify the notion that there are top level ports that the
> > > > > application might see, and some of those top level ports are parents to
> > > > > subordinate ports, which only the parent port should access directly. If thats
> > > > > all you want to encode, there are far easier ways to do it:
> > > > >
> > > > > struct rte_eth_shared_data {
> > > > > < existing bits >
> > > > > struct rte_eth_port_list {
> > > > > struct rte_eth_port_list *children;
> > > > > struct rte_eth_port_list *parent;
> > > > > };
> > > > > };
> > > > >
> > > > >
> > > > > Build an api around a structure like that, so that the parent/child relationship
> > > > > is globally clear, and this would be much easier, especially if you want to
> > > > > continue asserting that the notion of synchronization/exclusion is an exercise
> > > > > left to the application.
> > > >
> > > > Not only Neil.
> > > > An owner can be something else than a port.
> > > > An owner can be an app process (multi-processes).
> > > > An owner can be a library.
> > > > The intent is really to solve the generic problem of which code
> > > > is managing a port.
> > > >
> > > I don't see how this precludes any part of what you just said. Define the
> > > rte_eth_port_list externally to the shared_data struct and allow any object you
> > > want to allocate it, then anything you want to control a heirarchy of ports can
> > > do so without issue, and the structure is far more clear than an opaque id that
> > > carries subtle semantic ordering with it.
> >
> > Sorry, I don't understand. Please could you rephrase?
> >
>
> Sure, I'm saying the fact that you want an owner to be an object
> (library/port/process) rather than strictly an execution context
> (process/thread) doesn't preclude what I'm proposing above. You can create a
> generic version of the strcture I propose above like so:
>
> struct rte_obj_heirarchy {
> struct rte_obj_heirarchy *children;
> struct rte_obj_heirarchy *parent;
> void *owner_data; /* optional */
> };
>
> And embed that structure in any object you would like to give a representative
> heirarchy to, you then have a fairly simple api
>
> struct rte_obj_heirarchy *heirarchy_alloc();
> bool heirarchy_set(struct rte_obj_heirarchy *parent, struct rte_obj_heirarcy *child)
> void heirarchy_release(struct rte_obj_heirarchy *obj)
>
> That gives you the privately held list relationship I think you are in part
> looking for (i.e. the ability for a failsafe device to iterate over the ports it
> is in control of), without the awkwardness of the ordinal priority that the
> current implementation imposes.
>
> In summary, if what you want is ownership in the strictest sense of the word
> (i.e. mutually exclusive access, which I think makes sense), then using a lock
> and flag is really the simplest way to go. If instead what you want is a
> heirarchical relationship where you can iterate over a limited set of objects
> (the failsafe child port example), then the above is what you want.
>
>
> The soution Matan is providing does some of each of these things, but comes with
> very odd side effects
>
> It offers a level of mutual exclusion, in that only one
> object can own another at a time, but does so in a way that introduces this very
> atypical ordinality (once an ownership object is created with owner_new, any
> previously created ownership object will be denied the ability to take ownership
> of a port)
Why is that?
As I understand current code: any owner id between 1 and next_owner_id
is considered as valid.
Konstantin
>
> It also offers a level of filtering (in that if you can set the ownership id of
> a given set of object to the value X, you can then iterate over them by
> iterating over all objects of that type, and filtering on their id), but it
> offers no clear in-memory relationship between parent and children (i.e. if you
> were to look at at an object in a debugger and see that it was owned by owner id
> X, it would provide you with no indicator of what object held the allocated
> ownership object assigned id X. My proposal trades a few bytes of data in
> exchage for a global clear, definitive heirarcy relationship. And if you add an
> api call and a spinlock, you can easily graft on mutual exclusion here, by
> blocking access to objects that arent the immediate parent of a given object.
>
> Neil
>
>
>
> subsequently created object
next prev parent reply other threads:[~2018-01-20 12:54 UTC|newest]
Thread overview: 212+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-28 11:57 [dpdk-dev] [PATCH 0/5] ethdev: Port ownership Matan Azrad
2017-11-28 11:57 ` [dpdk-dev] [PATCH 1/5] ethdev: free a port by a dedicated API Matan Azrad
2017-11-28 11:57 ` [dpdk-dev] [PATCH 2/5] ethdev: add port ownership Matan Azrad
2017-11-30 12:36 ` Neil Horman
2017-11-30 13:24 ` Gaëtan Rivet
2017-11-30 14:30 ` Matan Azrad
2017-11-30 15:09 ` Gaëtan Rivet
2017-11-30 15:43 ` Matan Azrad
2017-12-01 12:09 ` Neil Horman
2017-12-03 8:04 ` Matan Azrad
2017-12-03 11:10 ` Ananyev, Konstantin
2017-12-03 13:46 ` Matan Azrad
2017-12-04 16:01 ` Neil Horman
2017-12-04 18:10 ` Matan Azrad
2017-12-04 22:30 ` Neil Horman
2017-12-05 6:08 ` Matan Azrad
2017-12-05 10:05 ` Bruce Richardson
2017-12-08 11:35 ` Thomas Monjalon
2017-12-08 12:31 ` Neil Horman
2017-12-21 17:06 ` Thomas Monjalon
2017-12-21 17:43 ` Neil Horman
2017-12-21 19:37 ` Matan Azrad
2017-12-21 20:14 ` Neil Horman
2017-12-21 21:57 ` Matan Azrad
2017-12-22 14:26 ` Neil Horman
2017-12-23 22:36 ` Matan Azrad
2017-12-29 16:56 ` Neil Horman
2017-12-05 19:26 ` Neil Horman
2017-12-08 11:06 ` Thomas Monjalon
2017-12-05 11:12 ` Ananyev, Konstantin
2017-12-05 11:44 ` Ananyev, Konstantin
2017-12-05 11:53 ` Thomas Monjalon
2017-12-05 14:56 ` Bruce Richardson
2017-12-05 14:57 ` Ananyev, Konstantin
2017-12-05 11:47 ` Thomas Monjalon
2017-12-05 15:13 ` Ananyev, Konstantin
2017-12-05 15:49 ` Thomas Monjalon
2017-11-28 11:57 ` [dpdk-dev] [PATCH 3/5] net/failsafe: free an eth port by a dedicated API Matan Azrad
2017-11-28 11:58 ` [dpdk-dev] [PATCH 4/5] net/failsafe: use ownership mechanism to own ports Matan Azrad
2017-11-28 11:58 ` [dpdk-dev] [PATCH 5/5] app/testpmd: adjust ethdev port ownership Matan Azrad
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 0/6] ethdev: " Matan Azrad
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 1/6] ethdev: fix port data reset timing Matan Azrad
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 2/6] ethdev: add port ownership Matan Azrad
2018-01-10 13:36 ` Ananyev, Konstantin
2018-01-10 16:58 ` Matan Azrad
2018-01-11 12:40 ` Ananyev, Konstantin
2018-01-11 14:51 ` Matan Azrad
2018-01-12 0:02 ` Ananyev, Konstantin
2018-01-12 7:24 ` Matan Azrad
2018-01-15 11:45 ` Ananyev, Konstantin
2018-01-15 13:09 ` Matan Azrad
2018-01-15 18:43 ` Ananyev, Konstantin
2018-01-16 8:04 ` Matan Azrad
2018-01-16 19:11 ` Ananyev, Konstantin
2018-01-16 20:32 ` Matan Azrad
2018-01-17 11:24 ` Ananyev, Konstantin
2018-01-17 12:05 ` Matan Azrad
2018-01-17 12:54 ` Ananyev, Konstantin
2018-01-17 13:10 ` Matan Azrad
2018-01-17 16:52 ` Ananyev, Konstantin
2018-01-17 18:02 ` Matan Azrad
2018-01-17 20:34 ` Matan Azrad
2018-01-18 14:17 ` Ananyev, Konstantin
2018-01-18 14:26 ` Matan Azrad
2018-01-18 14:41 ` Ananyev, Konstantin
2018-01-18 14:45 ` Matan Azrad
2018-01-18 14:51 ` Ananyev, Konstantin
2018-01-18 15:00 ` Matan Azrad
2018-01-17 14:00 ` Neil Horman
2018-01-17 17:01 ` Ananyev, Konstantin
2018-01-18 13:10 ` Neil Horman
2018-01-18 14:00 ` Matan Azrad
2018-01-18 16:54 ` Neil Horman
2018-01-18 17:20 ` Matan Azrad
2018-01-18 18:41 ` Neil Horman
2018-01-18 20:21 ` Matan Azrad
2018-01-19 1:41 ` Neil Horman
2018-01-19 7:14 ` Matan Azrad
2018-01-19 9:30 ` Bruce Richardson
2018-01-19 10:44 ` Matan Azrad
2018-01-19 13:30 ` Neil Horman
2018-01-19 13:57 ` Matan Azrad
2018-01-19 14:13 ` Thomas Monjalon
2018-01-19 15:27 ` Neil Horman
2018-01-19 17:17 ` Thomas Monjalon
2018-01-19 17:43 ` Neil Horman
2018-01-19 18:12 ` Thomas Monjalon
2018-01-19 19:47 ` Neil Horman
2018-01-19 20:19 ` Thomas Monjalon
2018-01-19 22:52 ` Neil Horman
2018-01-20 3:38 ` Tuxdriver
2018-01-20 12:54 ` Ananyev, Konstantin [this message]
2018-01-20 14:02 ` Thomas Monjalon
2018-01-19 12:55 ` Neil Horman
2018-01-19 13:52 ` Neil Horman
2018-01-18 16:27 ` Neil Horman
2018-01-17 17:58 ` Matan Azrad
2018-01-18 13:20 ` Neil Horman
2018-01-18 14:52 ` Matan Azrad
2018-01-19 13:57 ` Neil Horman
2018-01-19 14:07 ` Thomas Monjalon
2018-01-19 14:32 ` Neil Horman
2018-01-19 17:09 ` Thomas Monjalon
2018-01-19 17:37 ` Neil Horman
2018-01-19 18:10 ` Thomas Monjalon
2018-01-21 22:12 ` Ferruh Yigit
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 3/6] ethdev: synchronize port allocation Matan Azrad
2018-01-07 9:58 ` Matan Azrad
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 4/6] net/failsafe: free an eth port by a dedicated API Matan Azrad
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 5/6] net/failsafe: use ownership mechanism to own ports Matan Azrad
2018-01-08 10:32 ` Gaëtan Rivet
2018-01-08 11:16 ` Matan Azrad
2018-01-08 11:35 ` Gaëtan Rivet
2018-01-07 9:45 ` [dpdk-dev] [PATCH v2 6/6] app/testpmd: adjust ethdev port ownership Matan Azrad
2018-01-08 11:39 ` Gaëtan Rivet
2018-01-08 12:30 ` Matan Azrad
2018-01-08 13:30 ` Gaëtan Rivet
2018-01-08 13:55 ` Matan Azrad
2018-01-08 14:21 ` Gaëtan Rivet
2018-01-08 14:42 ` Matan Azrad
2018-01-16 5:53 ` Lu, Wenzhuo
2018-01-16 8:15 ` Matan Azrad
2018-01-17 0:46 ` Lu, Wenzhuo
2018-01-17 8:51 ` Matan Azrad
2018-01-18 0:53 ` Lu, Wenzhuo
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 0/7] Port ownership and syncronization Matan Azrad
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 1/7] ethdev: fix port data reset timing Matan Azrad
2018-01-18 17:00 ` Thomas Monjalon
2018-01-19 12:38 ` Ananyev, Konstantin
2018-03-05 11:24 ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit
2018-03-05 14:52 ` Matan Azrad
2018-03-05 15:06 ` Ferruh Yigit
2018-03-05 15:12 ` Matan Azrad
2018-03-27 22:37 ` Ferruh Yigit
2018-03-28 12:07 ` Matan Azrad
2018-03-30 10:39 ` Ferruh Yigit
2018-04-19 11:07 ` Ferruh Yigit
2018-04-25 12:16 ` Matan Azrad
2018-04-25 12:30 ` Ori Kam
2018-04-25 12:54 ` Ferruh Yigit
2018-04-25 14:01 ` Matan Azrad
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 2/7] ethdev: fix used portid allocation Matan Azrad
2018-01-18 17:00 ` Thomas Monjalon
2018-01-19 12:40 ` Ananyev, Konstantin
2018-01-20 16:48 ` Matan Azrad
2018-01-20 17:26 ` Ananyev, Konstantin
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 3/7] ethdev: add port ownership Matan Azrad
2018-01-18 21:11 ` Thomas Monjalon
2018-01-19 12:41 ` Ananyev, Konstantin
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 4/7] ethdev: synchronize port allocation Matan Azrad
2018-01-18 20:43 ` Thomas Monjalon
2018-01-18 20:52 ` Matan Azrad
2018-01-18 21:17 ` Thomas Monjalon
2018-01-19 12:47 ` Ananyev, Konstantin
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 5/7] net/failsafe: free an eth port by a dedicated API Matan Azrad
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 6/7] net/failsafe: use ownership mechanism to own ports Matan Azrad
2018-01-18 16:35 ` [dpdk-dev] [PATCH v3 7/7] app/testpmd: adjust ethdev port ownership Matan Azrad
2018-01-19 12:37 ` Ananyev, Konstantin
2018-01-19 12:51 ` Matan Azrad
2018-01-19 13:08 ` Ananyev, Konstantin
2018-01-19 13:35 ` Matan Azrad
2018-01-19 15:00 ` Gaëtan Rivet
2018-01-20 18:14 ` Matan Azrad
2018-01-22 10:17 ` Gaëtan Rivet
2018-01-22 11:22 ` Matan Azrad
2018-01-22 12:28 ` Ananyev, Konstantin
2018-01-22 13:22 ` Matan Azrad
2018-01-22 20:48 ` Ananyev, Konstantin
2018-01-23 8:54 ` Matan Azrad
2018-01-23 12:56 ` Gaëtan Rivet
2018-01-23 14:30 ` Matan Azrad
2018-01-25 9:36 ` Matan Azrad
2018-01-25 10:05 ` Thomas Monjalon
2018-01-25 11:15 ` Ananyev, Konstantin
2018-01-25 11:33 ` Thomas Monjalon
2018-01-25 11:55 ` Ananyev, Konstantin
2018-01-23 13:34 ` Ananyev, Konstantin
2018-01-23 14:18 ` Thomas Monjalon
2018-01-23 15:12 ` Ananyev, Konstantin
2018-01-23 15:18 ` Ananyev, Konstantin
2018-01-23 17:33 ` Thomas Monjalon
2018-01-23 21:18 ` Ananyev, Konstantin
2018-01-24 8:10 ` Thomas Monjalon
2018-01-24 18:30 ` Ananyev, Konstantin
2018-01-25 10:55 ` Thomas Monjalon
2018-01-25 11:09 ` Ananyev, Konstantin
2018-01-25 11:27 ` Thomas Monjalon
2018-01-23 14:43 ` Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 0/7] Port ownership and syncronization Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 1/7] ethdev: fix port data reset timing Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 2/7] ethdev: fix used portid allocation Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 3/7] ethdev: add port ownership Matan Azrad
2018-01-21 20:43 ` Ferruh Yigit
2018-01-21 20:46 ` Ferruh Yigit
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 4/7] ethdev: synchronize port allocation Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 5/7] net/failsafe: free an eth port by a dedicated API Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 6/7] net/failsafe: use ownership mechanism to own ports Matan Azrad
2018-01-20 21:24 ` [dpdk-dev] [PATCH v4 7/7] app/testpmd: adjust ethdev port ownership Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 0/7] Port ownership and synchronization Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 1/7] ethdev: fix port data reset timing Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 2/7] ethdev: fix used portid allocation Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 3/7] ethdev: add port ownership Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 4/7] ethdev: synchronize port allocation Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 5/7] net/failsafe: free an eth port by a dedicated API Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 6/7] net/failsafe: use ownership mechanism to own ports Matan Azrad
2018-01-22 16:38 ` [dpdk-dev] [PATCH v5 7/7] app/testpmd: adjust ethdev port ownership Matan Azrad
2018-01-25 1:47 ` Lu, Wenzhuo
2018-01-25 8:30 ` Matan Azrad
2018-01-26 0:50 ` Lu, Wenzhuo
2018-01-29 11:21 ` [dpdk-dev] [PATCH v5 0/7] Port ownership and synchronization Matan Azrad
2018-01-31 19:53 ` Thomas Monjalon
2018-01-25 14:35 ` [dpdk-dev] [PATCH v3 0/7] Port ownership and syncronization Ferruh Yigit
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