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From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Matan Azrad <matan@mellanox.com>,
	Adrien Mazarguil <adrien.mazarguil@6wind.com>,
	Gaetan Rivet <gaetan.rivet@6wind.com>
Cc: Thomas Monjalon <thomas@monjalon.net>, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v6 1/6] ethdev: add devop to check removal status
Date: Thu, 18 Jan 2018 17:18:22 +0000	[thread overview]
Message-ID: <2ffac5e9-6be5-0c82-18c4-8b72710630ae@intel.com> (raw)
In-Reply-To: <1516274834-19755-2-git-send-email-matan@mellanox.com>

On 1/18/2018 11:27 AM, Matan Azrad wrote:
> There is time between the physical removal of the device until PMDs get
> a RMV interrupt. At this time DPDK PMDs and applications still don't
> know about the removal.
> 
> Current removal detection is achieved only by registration to device RMV
> event and the notification comes asynchronously. So, there is no option
> to detect a device removal synchronously.
> Applications and other DPDK entities may want to check a device removal
> synchronously and to take an immediate decision accordingly.

So we will have two methods to detect device removal, one is asynchronous as you
mentioned.
Device removal will cause an interrupt which trigger to run user callback.

New method is synchronous, but still triggered from application. I mean
application should do a rte_eth_dev_is_removed() to learn about status, what is
the use case here, polling continuously? Won't this also cause some latency
unless you dedicate a core just polling device status?

> 
> Add new dev op called is_removed to allow DPDK entities to check an
> Ethernet device removal status immediately.
> 
> Signed-off-by: Matan Azrad <matan@mellanox.com>
> Acked-by: Thomas Monjalon <thomas@monjalon.net>
> ---
>  lib/librte_ether/rte_ethdev.c           | 28 +++++++++++++++++++++++++---
>  lib/librte_ether/rte_ethdev.h           | 20 ++++++++++++++++++++
>  lib/librte_ether/rte_ethdev_version.map |  1 +
>  3 files changed, 46 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index b349599..c93cec1 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -114,7 +114,8 @@ enum {
>  rte_eth_find_next(uint16_t port_id)
>  {
>  	while (port_id < RTE_MAX_ETHPORTS &&
> -	       rte_eth_devices[port_id].state != RTE_ETH_DEV_ATTACHED)
> +	       rte_eth_devices[port_id].state != RTE_ETH_DEV_ATTACHED &&
> +	       rte_eth_devices[port_id].state != RTE_ETH_DEV_REMOVED)

If device is removed, why we are not allowed to re-use port_id assigned to it?
Overall I am not clear with RTE_ETH_DEV_REMOVED state, why we are not directly
setting RTE_ETH_DEV_UNUSED?

And state RTE_ETH_DEV_REMOVED set in ethdev layer, and ethdev layer won't let
reusing it, so what changes the state of dev? Will it stay as it is during
lifetime of the application?

>  		port_id++;
>  
>  	if (port_id >= RTE_MAX_ETHPORTS)
> @@ -262,8 +263,7 @@ struct rte_eth_dev *
>  rte_eth_dev_is_valid_port(uint16_t port_id)
>  {
>  	if (port_id >= RTE_MAX_ETHPORTS ||
> -	    (rte_eth_devices[port_id].state != RTE_ETH_DEV_ATTACHED &&
> -	     rte_eth_devices[port_id].state != RTE_ETH_DEV_DEFERRED))
> +	    (rte_eth_devices[port_id].state == RTE_ETH_DEV_UNUSED))
>  		return 0;
>  	else
>  		return 1;
> @@ -1094,6 +1094,28 @@ struct rte_eth_dev *
>  }
>  
>  int
> +rte_eth_dev_is_removed(uint16_t port_id)
> +{
> +	struct rte_eth_dev *dev;
> +	int ret;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, 0);
> +
> +	dev = &rte_eth_devices[port_id];
> +
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->is_removed, 0);
> +
> +	if (dev->state == RTE_ETH_DEV_REMOVED)
> +		return 1;

Isn't this conflict with below API documentation:

"
 * @return
 *   - 0 when the Ethernet device is removed, otherwise 1.
"

> +
> +	ret = dev->dev_ops->is_removed(dev);
> +	if (ret != 0)
> +		dev->state = RTE_ETH_DEV_REMOVED;

It isn't clear what "dev_ops->is_removed(dev)" should return, and this causing
incompatible usages in PMDs by time.
Please add some documentation about expected return values for dev_ops.


And this not real remove, PMD signals us and we stop using that device, but
device can be there, right?
If there is a real removal, can be possible to use eal hotplug?

<...>

  reply	other threads:[~2018-01-18 17:18 UTC|newest]

Thread overview: 98+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02 15:42 [dpdk-dev] [PATCH 0/3] Fail-safe fix removal handling lack Matan Azrad
2017-11-02 15:42 ` [dpdk-dev] [PATCH 1/3] net/failsafe: " Matan Azrad
2017-11-06  8:19   ` Gaëtan Rivet
2017-11-02 15:42 ` [dpdk-dev] [PATCH 2/3] net/mlx4: adjust removal error Matan Azrad
2017-11-03 13:05   ` Adrien Mazarguil
2017-11-05  6:52     ` Matan Azrad
2017-11-06 16:51       ` Adrien Mazarguil
2017-11-02 15:42 ` [dpdk-dev] [PATCH 3/3] net/mlx5: " Matan Azrad
2017-11-03 13:06   ` Adrien Mazarguil
2017-11-05  6:57     ` Matan Azrad
2017-12-13 14:29 ` [dpdk-dev] [PATCH v2 0/4] Fail-safe fix removal handling lack Matan Azrad
2017-12-13 14:29   ` [dpdk-dev] [PATCH v2 1/4] ethdev: add devop to check removal status Matan Azrad
2017-12-13 14:29   ` [dpdk-dev] [PATCH v2 2/4] net/mlx4: support a device removal check operation Matan Azrad
2017-12-13 14:29   ` [dpdk-dev] [PATCH v2 3/4] net/mlx5: " Matan Azrad
2017-12-13 14:29   ` [dpdk-dev] [PATCH v2 4/4] net/failsafe: fix removed device handling Matan Azrad
2017-12-13 15:16     ` Gaëtan Rivet
2017-12-13 15:48       ` Matan Azrad
2017-12-13 16:09         ` Gaëtan Rivet
2017-12-13 17:09           ` Thomas Monjalon
2017-12-14 10:40             ` Matan Azrad
2017-12-13 21:55           ` Gaëtan Rivet
2017-12-14 10:40             ` Matan Azrad
2017-12-14 10:48               ` Gaëtan Rivet
2017-12-14 13:07                 ` Matan Azrad
2017-12-14 13:27                   ` Gaëtan Rivet
2017-12-14 14:43                     ` Matan Azrad
2017-12-19 17:10   ` [dpdk-dev] [PATCH v3 0/6] Fail-safe\ethdev: fix removal handling lack Matan Azrad
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 1/6] ethdev: add devop to check removal status Matan Azrad
2017-12-19 17:20       ` Stephen Hemminger
2017-12-19 17:24         ` Matan Azrad
2017-12-19 20:51           ` Thomas Monjalon
2017-12-19 22:13             ` Gaëtan Rivet
2017-12-20  8:39               ` Matan Azrad
2018-01-07  9:53       ` Thomas Monjalon
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 2/6] net/mlx4: support a device removal check operation Matan Azrad
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 3/6] net/mlx5: " Matan Azrad
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 4/6] ethdev: adjust APIs removal error report Matan Azrad
2018-01-07  9:56       ` Thomas Monjalon
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 5/6] ethdev: adjust flow " Matan Azrad
2018-01-07  9:58       ` Thomas Monjalon
2017-12-19 17:10     ` [dpdk-dev] [PATCH v3 6/6] net/failsafe: fix removed device handling Matan Azrad
2017-12-19 22:21       ` Gaëtan Rivet
2017-12-20 10:58         ` Matan Azrad
2018-01-08 10:57           ` Gaëtan Rivet
2018-01-08 12:55             ` Matan Azrad
2018-01-08 13:46               ` Gaëtan Rivet
2018-01-08 14:00                 ` Matan Azrad
2018-01-08 14:31                   ` Gaëtan Rivet
2018-01-10 12:30     ` [dpdk-dev] [PATCH v4 0/6] Fail-safe\ethdev: fix removal handling lack Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 1/6] ethdev: add devop to check removal status Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 2/6] net/mlx4: support a device removal check operation Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 3/6] net/mlx5: " Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 4/6] ethdev: adjust APIs removal error report Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 5/6] ethdev: adjust flow " Matan Azrad
2018-01-10 12:31       ` [dpdk-dev] [PATCH v4 6/6] net/failsafe: fix removed device handling Matan Azrad
2018-01-10 12:43         ` Matan Azrad
2018-01-10 13:51           ` Gaëtan Rivet
2018-01-10 13:47         ` Gaëtan Rivet
2018-01-17 20:19       ` [dpdk-dev] [PATCH v5 0/6] Fail-safe\ethdev: fix removal handling lack Matan Azrad
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 1/6] ethdev: add devop to check removal status Matan Azrad
2018-01-17 20:40           ` Ferruh Yigit
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 2/6] net/mlx4: support a device removal check operation Matan Azrad
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 3/6] net/mlx5: " Matan Azrad
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 4/6] ethdev: adjust APIs removal error report Matan Azrad
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 5/6] ethdev: adjust flow " Matan Azrad
2018-01-17 20:19         ` [dpdk-dev] [PATCH v5 6/6] net/failsafe: fix removed device handling Matan Azrad
2018-01-18  8:44           ` Gaëtan Rivet
2018-01-18 11:27         ` [dpdk-dev] [PATCH v6 0/6] Fail-safe\ethdev: fix removal handling lack Matan Azrad
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 1/6] ethdev: add devop to check removal status Matan Azrad
2018-01-18 17:18             ` Ferruh Yigit [this message]
2018-01-18 17:57               ` Adrien Mazarguil
2018-01-18 18:02               ` Matan Azrad
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 2/6] net/mlx4: support a device removal check operation Matan Azrad
2018-01-18 16:59             ` Adrien Mazarguil
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 3/6] net/mlx5: " Matan Azrad
2018-01-18 16:59             ` Adrien Mazarguil
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 4/6] ethdev: adjust APIs removal error report Matan Azrad
2018-01-18 17:31             ` Ferruh Yigit
2018-01-18 18:10               ` Matan Azrad
2018-01-19 16:19                 ` Ferruh Yigit
2018-01-19 17:35                   ` Ananyev, Konstantin
2018-01-19 17:54                   ` Thomas Monjalon
2018-01-19 18:13                     ` Ferruh Yigit
2018-01-19 18:16                       ` Thomas Monjalon
2018-01-20 19:04                         ` Matan Azrad
2018-01-20 20:28                           ` Thomas Monjalon
2018-01-20 20:45                             ` Matan Azrad
2018-01-21 20:07                   ` Ferruh Yigit
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 5/6] ethdev: adjust flow " Matan Azrad
2018-01-18 11:27           ` [dpdk-dev] [PATCH v6 6/6] net/failsafe: fix removed device handling Matan Azrad
2018-01-20 21:12           ` [dpdk-dev] [PATCH v7 0/6] Fail-safe\ethdev: fix removal handling lack Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 1/6] ethdev: add devop to check removal status Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 2/6] net/mlx4: support a device removal check operation Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 3/6] net/mlx5: " Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 4/6] ethdev: adjust APIs removal error report Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 5/6] ethdev: adjust flow " Matan Azrad
2018-01-20 21:12             ` [dpdk-dev] [PATCH v7 6/6] net/failsafe: fix removed device handling Matan Azrad
2018-01-21 20:28             ` [dpdk-dev] [PATCH v7 0/6] Fail-safe\ethdev: fix removal handling lack Ferruh Yigit

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