DPDK patches and discussions
 help / color / mirror / Atom feed
From: Matan Azrad <matan@mellanox.com>
To: Thomas Monjalon <thomas@monjalon.net>,
	Ferruh Yigit <ferruh.yigit@intel.com>,
	"Ananyev, Konstantin" <konstantin.ananyev@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
	Adrien Mazarguil <adrien.mazarguil@6wind.com>,
	Gaetan Rivet <gaetan.rivet@6wind.com>,
	"Andrew Rybchenko" <arybchenko@solarflare.com>,
	Alejandro Lucero <alejandro.lucero@netronome.com>,
	Jerin Jacob <jerin.jacob@caviumnetworks.com>,
	Hemant Agrawal <hemant.agrawal@nxp.com>,
	Shahaf Shuler <shahafs@mellanox.com>,
	Olivier MATZ <olivier.matz@6wind.com>,
	"Zhang, Helin" <helin.zhang@intel.com>
Subject: Re: [dpdk-dev] [PATCH v6 4/6] ethdev: adjust APIs removal error report
Date: Sat, 20 Jan 2018 19:04:21 +0000	[thread overview]
Message-ID: <AM6PR0502MB37976EF53B6CA50E0703CEB1D2EE0@AM6PR0502MB3797.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <3230393.d19WHEAjBn@xps>

Hi all

From: Thomas Monjalon, Friday, January 19, 2018 8:17 PM
> 19/01/2018 19:13, Ferruh Yigit:
> > On 1/19/2018 5:54 PM, Thomas Monjalon wrote:
> > > 19/01/2018 17:19, Ferruh Yigit:
> > >> On 1/18/2018 6:10 PM, Matan Azrad wrote:
> > >>> From: Ferruh Yigit, Thursday, January 18, 2018 7:31 PM
> > >>>> This patch updates *all* ethdev public APIs to add if device is
> > >>>> removed check?
> > >>>
> > >>> Yes.
> > >>>
> > >>>> And each check goes to ethdev is_removed() dev_ops to ask if dev
> > >>>> is removed.
> > >>> Probably, if the REMOVED state setted in will not call device
> is_remove.
> > >>>
> > >>>> These must be better way of doing this, am I missing something.
> > >>>
> > >>> Suggest.
> > >>
> > >> With a silly analogy, this is like a blind person asking each time
> > >> if he is dead before talking to other person.

Just to accurate the analogy:)
This is like a blind person(application,ethdev) using its guide dog(ethdev device), every time the dog refuses to take action (error occurred), the blind person asks if the dog can be a guide dog anymore(removal error). 

> > >> At first glance I can think of a kind of watchdog timer can be
> > >> implemented in ethdev layer. It provides periodic checks and if
> > >> device is dead it calls the registered user callback function.
> > >>
> > >> This method presented as synchronous method but not triggered from
> > >> side where event happens, I mean not triggered from PMD but from
> application.
> > >> So does application doing polling continuously if device is dead?
> > >> Or if application is relying this patch to add a check in each API,
> > >> what happens if device removed during data processing, will app rely on
> asynchronous method?
> > >
> > > We cannot put a mutex on hardware removal :) So we have to live with
> > > errors du to removal.
> > > If we are trying to configure a removed device, the error will be
> > > not related to the root cause.
> > > This patch is just trying to improve the situation by returning an
> > > appropriate error code if removal can be detected.
> > > Note: the check is run only if there is an error and if the removal
> > > is not already detected.
> > >
> > > If I understand well, you prefer relying only on asynchronous
> > > hotplug events? Even if they come really late?
> >
> > I think asynchronous hotplug events are better approach, but if they
> > are late I understand you need a solution.
> >
> > I assume issue is when device is removed, application can make API
> > calls until it detects the removal.
> >
> > For that case what do you think instead of ethdev abstraction layer
> > doing a translation, define a specific error type and return it from
> > PMDs to indicate that error is related to the missing device and
> > application will know device is no more there? And consistently use that
> error type in all PMDs.
> 
> Yes it is also a good solution.
> I think Matan proposed to integrate it in ethdev to avoid duplicating the
> same mechanism in every PMDs.
> 

Yes, as a lot of ethdev API code pieces do.

> > Or what do you think above suggested flexible watchdog timer
> > implementation in ethdev, so applications may be informed about missing
> device faster.
> 
> I think the watchdog would compete with hotplug events.
> So I prefer not integrating one more asynchronous mechanism for the same
> purpose.
> If we want polling, it can be an option to enable in EAL hotplug.

Konstantin wrote in another thread:
>+	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);

> I'd says these 2 checks have to be swapped.

Konstantin, Please explain why.

  reply	other threads:[~2018-01-20 19:04 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
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 [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=AM6PR0502MB37976EF53B6CA50E0703CEB1D2EE0@AM6PR0502MB3797.eurprd05.prod.outlook.com \
    --to=matan@mellanox.com \
    --cc=adrien.mazarguil@6wind.com \
    --cc=alejandro.lucero@netronome.com \
    --cc=arybchenko@solarflare.com \
    --cc=dev@dpdk.org \
    --cc=ferruh.yigit@intel.com \
    --cc=gaetan.rivet@6wind.com \
    --cc=helin.zhang@intel.com \
    --cc=hemant.agrawal@nxp.com \
    --cc=jerin.jacob@caviumnetworks.com \
    --cc=konstantin.ananyev@intel.com \
    --cc=olivier.matz@6wind.com \
    --cc=shahafs@mellanox.com \
    --cc=thomas@monjalon.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).