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From: Thomas Monjalon <thomas@monjalon.net>
To: Jan Blunck <jblunck@infradead.org>
Cc: dev@dpdk.org, Gaetan Rivet <gaetan.rivet@6wind.com>
Subject: Re: [dpdk-dev] [PATCH v5 5/7] bus: add helper to find a bus from a device name
Date: Thu, 29 Jun 2017 10:21:56 +0200	[thread overview]
Message-ID: <1847454.cyn7CixU0U@xps> (raw)
In-Reply-To: <CALe+Z03YBc=n+QXP3O4oUunENi30RLdKK4-3BSaDNTpi0YmYAw@mail.gmail.com>

29/06/2017 09:56, Jan Blunck:
> On Wed, Jun 28, 2017 at 7:03 PM, Thomas Monjalon <thomas@monjalon.net> wrote:
> > 27/06/2017 20:55, Jan Blunck:
> >> On Wed, Jun 21, 2017 at 1:30 AM, Gaetan Rivet <gaetan.rivet@6wind.com> wrote:
> >> >  /**
> >> > + * Find a bus capable of identifying a device.
> >> > + *
> >> > + * @param str
> >> > + *   A device identifier (PCI address, virtual PMD name, ...).
> >> > + *
> >> > + * @return
> >> > + *   A valid bus handle if found.
> >> > + *   NULL if no bus is able to parse this device.
> >> > + */
> >> > +struct rte_bus *rte_bus_from_dev(const char *str);
> >>
> >> I still don't agree with this. The bus name should be passed
> >> explicitly by the user of the API.
> >>
> >> NAK.
> >
> > Please explain why you think the bus name should be explicit.
> > If the bus is ambiguous, it can be explicited by the user.
> >
> > I see some good benefits in being tolerant with the bus/device
> > representation. It provides a smooth transition to the bus model.
> >
> 
> We build libraries. The applications we build with the help of those
> libraries get notified by the OS about device events. Those devices
> are chields of their parent bus. At the time the event is fired the OS
> already knows about:
> 
> - the bus name (parent)
> - the device name (child)
> - additional event parameters (environment)
> 
> Blame me that I probably spent too much time with Kay Sievers and
> GregKH to understand that device naming is easy to get wrong. Just
> look at the hyperv device names and how they switched to the UUID
> scheme. I don't think that hyperv is the only bus that uses UUID as
> device identification. We should not codify a policy of how to deduce
> a bus name from a given device name if that is knowledge that is
> already present externally. Otherwise I fear this part of the EAL will
> be subject to constant churn.

OK I understand your point that it is a weak identification.
It is as weak as what we have currently.
It works at least when we have only PCI and VDEV.
However it does not prevent to use a strong identification with
bus and parent names.
I see rte_bus_from_dev() as a helper to transition to the new strong
identification model. So we could remove it in few releases.
Does it make sense?

  reply	other threads:[~2017-06-29  8:21 UTC|newest]

Thread overview: 123+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-24 15:12 [dpdk-dev] [PATCH 0/9] rte_bus parse API Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 1/9] bus: fix bus name registration Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 2/9] bus: verify bus name on registration Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 3/9] bus: introduce parsing functionality Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 4/9] vdev: implement parse bus operation Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 5/9] pci: " Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 6/9] bus: add helper to find bus from a name Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 7/9] bus: add helper to find a bus from a device name Gaetan Rivet
2017-06-07 17:28   ` Jan Blunck
2017-06-07 20:03     ` Gaëtan Rivet
2017-06-08 10:45       ` Jan Blunck
2017-06-08 11:36         ` Gaëtan Rivet
2017-06-08 11:40           ` Jan Blunck
2017-06-08 12:51             ` Gaëtan Rivet
2017-06-10  8:50               ` Jan Blunck
2017-06-12 14:21                 ` Gaëtan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 8/9] vdev: expose bus name Gaetan Rivet
2017-05-24 15:12 ` [dpdk-dev] [PATCH 9/9] devargs: parse bus info Gaetan Rivet
2017-05-24 16:15 ` [dpdk-dev] [PATCH v2 0/9] rte_bus parse API Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 1/9] bus: fix bus name registration Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 2/9] bus: verify bus name on registration Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 3/9] bus: introduce parsing functionality Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 4/9] vdev: implement parse bus operation Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 5/9] pci: " Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 6/9] bus: add helper to find bus from a name Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 7/9] bus: add helper to find a bus from a device name Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 8/9] vdev: expose bus name Gaetan Rivet
2017-05-24 16:15   ` [dpdk-dev] [PATCH v2 9/9] devargs: parse bus info Gaetan Rivet
2017-06-01 10:08   ` [dpdk-dev] [PATCH v3 0/9] rte_bus parse API Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 1/9] bus: fix bus name registration Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 2/9] bus: verify bus name on registration Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 3/9] bus: introduce parsing functionality Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 4/9] vdev: implement parse bus operation Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 5/9] pci: " Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 6/9] bus: add helper to find bus from a name Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 7/9] bus: add helper to find a bus from a device name Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 8/9] vdev: expose bus name Gaetan Rivet
2017-06-01 10:08     ` [dpdk-dev] [PATCH v3 9/9] devargs: parse bus info Gaetan Rivet
2017-06-07 23:56     ` [dpdk-dev] [PATCH v4 0/9] rte_bus parse API Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 1/9] bus: fix bus name registration Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 2/9] bus: verify bus name on registration Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 3/9] bus: introduce parsing functionality Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 4/9] vdev: implement parse bus operation Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 5/9] pci: " Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 6/9] bus: add helper to find a bus from a bus name Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 7/9] bus: add helper to find a bus from a device name Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 8/9] vdev: expose bus name Gaetan Rivet
2017-06-07 23:56       ` [dpdk-dev] [PATCH v4 9/9] devargs: parse bus info Gaetan Rivet
2017-06-20 23:30       ` [dpdk-dev] [PATCH v5 0/7] rte_bus parse API Gaetan Rivet
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 1/7] bus: fix bus name registration Gaetan Rivet
2017-06-27 15:53           ` Bruce Richardson
2017-06-27 19:19           ` Jan Blunck
2017-07-04  1:05             ` Gaëtan Rivet
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 2/7] bus: introduce parsing functionality Gaetan Rivet
2017-06-27 15:54           ` Bruce Richardson
2017-06-27 19:26           ` Jan Blunck
2017-07-04  1:35             ` Gaëtan Rivet
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 3/7] vdev: implement parse bus operation Gaetan Rivet
2017-06-27 15:59           ` Bruce Richardson
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 4/7] pci: " Gaetan Rivet
2017-06-27 16:18           ` Bruce Richardson
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 5/7] bus: add helper to find a bus from a device name Gaetan Rivet
2017-06-27 16:26           ` Bruce Richardson
2017-06-27 18:55           ` Jan Blunck
2017-06-28 17:03             ` Thomas Monjalon
2017-06-29  7:56               ` Jan Blunck
2017-06-29  8:21                 ` Thomas Monjalon [this message]
2017-06-29 10:23                 ` Gaëtan Rivet
2017-06-29 10:30                   ` Richardson, Bruce
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 6/7] vdev: expose bus name Gaetan Rivet
2017-06-20 23:30         ` [dpdk-dev] [PATCH v5 7/7] devargs: parse bus info Gaetan Rivet
2017-06-27 16:01         ` [dpdk-dev] [PATCH v5 0/7] rte_bus parse API Bruce Richardson
2017-07-04  0:58         ` [dpdk-dev] [PATCH v6 0/6] " Gaetan Rivet
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 1/6] bus: fix bus name registration Gaetan Rivet
2017-07-04 21:43             ` [dpdk-dev] [PATCH] bus: fix driver registration Thomas Monjalon
2017-07-05  5:47               ` Shreyansh Jain
2017-07-05  6:01                 ` Shreyansh Jain
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 2/6] bus: introduce parsing functionality Gaetan Rivet
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 3/6] vdev: implement parse bus operation Gaetan Rivet
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 4/6] pci: " Gaetan Rivet
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 5/6] bus: add helper to find a bus from a device name Gaetan Rivet
2017-07-04 12:28             ` Gaëtan Rivet
2017-07-04  0:58           ` [dpdk-dev] [PATCH v6 6/6] devargs: parse bus info Gaetan Rivet
2017-07-04 23:55           ` [dpdk-dev] [PATCH v7 0/6] rte_bus parse API Gaetan Rivet
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 1/6] bus: fix driver registration Gaetan Rivet
2017-07-05 13:03               ` Shreyansh Jain
2017-07-06  6:05               ` santosh
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 2/6] bus: introduce parsing functionality Gaetan Rivet
2017-07-05 13:04               ` Shreyansh Jain
2017-07-06  9:19               ` santosh
2017-07-06 12:30                 ` Gaëtan Rivet
2017-07-06 13:12                   ` santosh
2017-07-06 13:30                     ` Gaëtan Rivet
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 3/6] vdev: implement parse bus operation Gaetan Rivet
2017-07-05 13:16               ` Shreyansh Jain
2017-07-06  9:35               ` santosh
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 4/6] pci: " Gaetan Rivet
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 5/6] bus: add helper to find a bus from a device name Gaetan Rivet
2017-07-05 13:35               ` Shreyansh Jain
2017-07-05 13:45                 ` Gaëtan Rivet
2017-07-05 14:12                   ` Shreyansh Jain
2017-07-06 10:10                   ` Thomas Monjalon
2017-07-06 11:37                     ` Gaëtan Rivet
2017-07-04 23:55             ` [dpdk-dev] [PATCH v7 6/6] devargs: parse bus info Gaetan Rivet
2017-07-05 18:03               ` Stephen Hemminger
2017-07-06  9:07               ` Shreyansh Jain
2017-07-06 10:00                 ` Gaëtan Rivet
2017-07-06 13:17                   ` Shreyansh Jain
2017-07-07  0:03             ` [dpdk-dev] [PATCH v8 0/6] rte_bus parse API Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 1/6] bus: fix driver registration Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 2/6] bus: introduce parsing functionality Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 3/6] vdev: implement parse bus operation Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 4/6] pci: " Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 5/6] bus: add helper to find a bus from a device name Gaetan Rivet
2017-07-07  0:03               ` [dpdk-dev] [PATCH v8 6/6] devargs: parse bus info Gaetan Rivet
2017-07-07  0:45                 ` Stephen Hemminger
2017-07-07  8:31                   ` Gaëtan Rivet
2017-07-08 20:31                     ` Thomas Monjalon
2017-07-08 20:30               ` [dpdk-dev] [PATCH v8 0/6] rte_bus parse API Thomas Monjalon
2017-06-07 17:22 ` [dpdk-dev] [PATCH 0/9] " Jan Blunck
2017-06-07 19:55   ` Gaëtan Rivet
2017-06-08 11:38     ` Jan Blunck
2017-06-08 13:04       ` Gaëtan Rivet

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