From: Shreyansh Jain <shreyansh.jain@nxp.com>
To: "Trahe, Fiona" <fiona.trahe@intel.com>
Cc: Hemant Agrawal <hemant.agrawal@nxp.com>,
"Xu, Rosen" <rosen.xu@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v1 1/5] rawdev: introduce raw device library support
Date: Fri, 12 Jan 2018 20:30:54 +0530 [thread overview]
Message-ID: <4adc1036-6d91-a550-a80a-37347dae184c@nxp.com> (raw)
In-Reply-To: <348A99DA5F5B7549AA880327E580B435892F0D40@IRSMSX101.ger.corp.intel.com>
Hello Fiona,
Apologies for delay in my response.
Some comments inline...
On Monday 08 January 2018 08:21 PM, Trahe, Fiona wrote:
>
>
>> -----Original Message-----
>> From: Shreyansh Jain [mailto:shreyansh.jain@nxp.com]
>> Sent: Monday, January 8, 2018 2:10 PM
>> To: Trahe, Fiona <fiona.trahe@intel.com>
>> Cc: Hemant Agrawal <hemant.agrawal@nxp.com>; Xu, Rosen <rosen.xu@intel.com>; dev@dpdk.org
>> Subject: Re: [PATCH v1 1/5] rawdev: introduce raw device library support
>>
>> Hello Fiona,
>>
>> On Saturday 06 January 2018 07:10 PM, Trahe, Fiona wrote:
>>> Hi Shreyansh,
>>>
>>> This looks like a useful generic device, thanks. Some comments below.
>>
>> Thanks for taking interest and sending your review.
>> I have some responses inline....
>> (And I have shortened the original email)
>>
>> [...]
>>
>>>> +#include "rte_rawdev.h"
>>>> +#include "rte_rawdev_pmd.h"
>>>> +
>>>> +/* dynamic log identifier */
>>>> +int librawdev_logtype;
>>>> +
>>>> +/* Maximum rawdevices supported by system.
>>>> + */
>>>> +#define RTE_MAX_RAWDEVPORTS 10
>>> [Fiona] Typo in comment above? There's RTE_RAWDEV_MAX_DEVS, RTE_MAX_RAWDEVS and
>> RTE_MAX_RAWDEVPORTS. Are all 3 necessary and what's the relationship between ports and devs?
>>
>> This is a stupid mistake by me. It should be only RTE_RAWDEV_MAX_DEVS.
>> RTE_MAX_RAWDEVS is useless and I will remove RTE_MAX_RAWDEVPORTS.
>> They are intend the same thing - number of max devices supported.
>>
>>>
>>
>> [...]
>>
>>>> +
>>>> +/**
>>>> + * Allocate and set up a raw queue for a raw device.
>>>> + *
>>>> + * @param dev_id
>>>> + * The identifier of the device.
>>>> + * @param queue_id
>>>> + * The index of the raw queue to setup. The value must be in the range
>>>> + * [0, nb_raw_queues - 1] previously supplied to rte_rawdev_configure().
>>>> + *
>>>> + * @see rte_rawdev_queue_conf_get()
>>>> + *
>>>> + * @return
>>>> + * - 0: Success, raw queue correctly set up.
>>>> + * - <0: raw queue configuration failed
>>>> + */
>>> [Fiona] cut and paste error above - should be release.
>>
>> Indeed. Thanks for pointing out.
>> I will fix this.
>>
>>>
>>>> +int
>>>> +rte_rawdev_queue_release(uint16_t dev_id, uint16_t queue_id);
>>>> +/**
>>>> + * Get the number of raw queues on a specific raw device
>>>> + *
>>>> + * @param dev_id
>>>> + * Raw device identifier.
>>>> + * @return
>>>> + * - The number of configured raw queues
>>>> + */
>>>> +uint16_t
>>
>> [...]
>>
>>>> +
>>>> +/**
>>>> + * Allocates a new rawdev slot for an raw device and returns the pointer
>>>> + * to that slot for the driver to use.
>>>> + *
>>>> + * @param name
>>>> + * Unique identifier name for each device
>>>> + * @dev_priv_size
>>>> + * Private data allocated within rte_rawdev object.
>>>> + * @param socket_id
>>>> + * Socket to allocate resources on.
>>>> + * @return
>>>> + * - Slot in the rte_dev_devices array for a new device;
>>>> + */
>>>> +struct rte_rawdev *
>>>> +rte_rawdev_pmd_allocate(const char *name, size_t dev_private_size,
>>>> + int socket_id);
>>> [Fiona] The driver must allocate a unique name for each device, and the application presumably must
>> search through all devices using dev_count and dev_info_get for each
>>> until it finds a name it expects? But will the application always know the name chosen by the PMD? e.g.
>> driver type xyz might find 10 devices and call them xyz_0, xyz_1, xyz_2, etc
>>> The application wants to look for any or all xyz devices so must know the naming format used by the
>> PMD.
>>> Would it be useful to have 2 parts to the name, a type and an instance, to facilitate finding all devices of
>> a specific type?
>>
>> let me state what I have understood:
>>
>> There are two types of devices:
>> 1. which are scanned through a bus (PCI ...)
>> 2. which are created through vdev (devargs, vdev_init)
>>
>> for those which are scanned through a bus, it is easy to append a
>> "type_" string during device naming.
>> for those which are added through command line, this pattern would have
>> to be choosen by the application/user.
>>
>> further, a rawdevice doesn't have a specific type. So, type would be
>> purely be defined by the driver (scan) or the device name itself
>> (vdev_init).
>>
>> So, eventually the "type_" field would be left out for driver or
>> application to decide. framework (lib/librte_rawdev) would never
>> override/append to it.
>>
>> Is this understanding correct?
> [Fiona] Yes. I'm probably overcomplicating it.
> I was considering scanned devices and e.g. a case where 2 PMDs inadvertently pick the same name.
> One idea would be each driver would register a type string with the lib layer and
> all its device names must start with this, thus ensuring that each device name is unique.
> With the vdev devices the application can ensure device names are unique.
> A driver would not be allowed to use a name starting with a string which another PMD had already registered.
>
> This would allow looser coupling between the applications and the PMDs, as applications
> would not need to know the exact name format of device name, just know the type it wants to use
> and search for all devices with names starting with that string.
> But I'm probably anticipating issues which wouldn't happen in real world applications.
> i.e. though there may be many PMDs and applications in the dpdk codebase using this lib in future,
> it's likely only a small number will be compiled into any build so such name clashes are unlikely to occur.
> And the applications must be tightly coupled with the PMD anyway to make use of the device, so
> that's probably not a concern either.
I agree with the last line that applications have to be tightly coupled
with PMD in this case. That defines (or prevents defining) a lot of
semantics.
While creating the patches, even I was thinking of standardizing the
naming (taking hint from some of Gaetan's work on devargs) but I
couldn't think of a policy which can be enforced only by the rawlib.
I concur with you that conflicting naming in a real world scenario is
theoretically possible, irrespective of how rare it might be.
I suggest that we continue as is and expand this in future when we have
more clarity or even some real-world application samples.
You have any objections to this?
>
>>
>> I will send a v2 shortly with your comments. I will also try and think
>> through your suggestion about name containing "type_" - I do think it is
>> useful but not really sure how would it define semantics between driver
>> and application.
>>
>> -
>> Shreyansh
next prev parent reply other threads:[~2018-01-12 14:46 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-02 12:57 [dpdk-dev] [PATCH v1 0/5] Introduce generic 'rawdevice' support Shreyansh Jain
2018-01-02 12:57 ` [dpdk-dev] [PATCH v1 1/5] rawdev: introduce raw device library support Shreyansh Jain
2018-01-06 13:40 ` Trahe, Fiona
2018-01-08 14:09 ` Shreyansh Jain
2018-01-08 14:51 ` Trahe, Fiona
2018-01-12 15:00 ` Shreyansh Jain [this message]
2018-01-12 19:35 ` Trahe, Fiona
2018-01-14 22:42 ` Thomas Monjalon
2018-01-14 22:50 ` Thomas Monjalon
2018-01-02 12:57 ` [dpdk-dev] [PATCH v1 2/5] config: enable compilation of rawdev library Shreyansh Jain
2018-01-14 22:50 ` Thomas Monjalon
2018-01-02 12:57 ` [dpdk-dev] [PATCH v1 3/5] drivers/raw: introduce skeleton rawdev driver Shreyansh Jain
2018-01-14 22:54 ` Thomas Monjalon
2018-01-16 10:21 ` Shreyansh Jain
2018-01-16 10:34 ` Thomas Monjalon
2018-01-02 12:57 ` [dpdk-dev] [PATCH v1 4/5] config: enable compilation of rawdev skeleton driver Shreyansh Jain
2018-01-14 22:55 ` Thomas Monjalon
2018-01-02 12:57 ` [dpdk-dev] [PATCH v1 5/5] test: support for rawdev testcases Shreyansh Jain
2018-01-14 22:58 ` Thomas Monjalon
2018-01-16 10:07 ` Shreyansh Jain
2018-01-16 10:32 ` Thomas Monjalon
2018-01-14 23:00 ` [dpdk-dev] [PATCH v1 0/5] Introduce generic 'rawdevice' support Thomas Monjalon
2018-01-15 5:30 ` Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 00/10] " Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 01/10] rawdev: introduce raw device library support Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 02/10] rawdev: add attribute get and set support Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 03/10] rawdev: add buffer stream IO support Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 04/10] rawdev: support for extended stats Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 05/10] rawdev: support for firmware management Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 06/10] rawdev: add self test support Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 07/10] drivers/raw: introduce skeleton rawdev driver Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 08/10] drivers/raw: support for rawdev testcases Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 09/10] test: enable rawdev skeleton test Shreyansh Jain
2018-01-23 13:59 ` [dpdk-dev] [PATCH v2 10/10] maintainers: claim ownership of rawdev Shreyansh Jain
2018-01-25 22:21 ` [dpdk-dev] [PATCH v2 00/10] Introduce generic 'rawdevice' support Thomas Monjalon
2018-01-29 23:49 ` Thomas Monjalon
2018-01-30 6:31 ` Shreyansh Jain
2018-01-30 14:56 ` [dpdk-dev] [PATCH v3 00/11] " Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 01/11] rawdev: introduce raw device library support Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 02/11] rawdev: add attribute get and set support Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 03/11] rawdev: add buffer stream IO support Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 04/11] rawdev: support for extended stats Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 05/11] rawdev: support for firmware management Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 06/11] rawdev: add self test support Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 07/11] drivers/raw: introduce skeleton rawdev driver Shreyansh Jain
2018-01-30 16:48 ` Thomas Monjalon
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 08/11] drivers/raw: support for rawdev testcases Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 09/11] test: enable rawdev skeleton test Shreyansh Jain
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 10/11] maintainers: claim ownership of rawdev Shreyansh Jain
2018-01-30 16:50 ` Thomas Monjalon
2018-01-30 14:57 ` [dpdk-dev] [PATCH v3 11/11] doc: add rawdev library page Shreyansh Jain
2018-01-30 16:55 ` [dpdk-dev] [PATCH v3 00/11] Introduce generic 'rawdevice' support Thomas Monjalon
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 00/10] " Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 01/10] rawdev: introduce raw device library support Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 02/10] rawdev: add attribute get and set support Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 03/10] rawdev: add buffer stream IO support Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 04/10] rawdev: support for extended stats Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 05/10] rawdev: support for firmware management Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 06/10] rawdev: add self test support Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 07/10] drivers/raw: introduce skeleton rawdev driver Shreyansh Jain
2018-01-31 13:20 ` Thomas Monjalon
2018-01-31 13:31 ` Thomas Monjalon
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 08/10] drivers/raw: support for rawdev testcases Shreyansh Jain
2018-01-31 14:01 ` Thomas Monjalon
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 09/10] test: enable rawdev skeleton test Shreyansh Jain
2018-01-31 9:13 ` [dpdk-dev] [PATCH v4 10/10] doc: add rawdev library page and support Doxygen Shreyansh Jain
2018-01-31 14:45 ` [dpdk-dev] [PATCH v4 00/10] Introduce generic 'rawdevice' support Thomas Monjalon
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