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From: Stephen Hemminger <stephen@networkplumber.org>
To: Igor Ryzhov <iryzhov@nfware.com>
Cc: Elad Nachman <eladv6@gmail.com>,
	Ferruh Yigit <ferruh.yigit@intel.com>, dev <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 2/2] kni: fix rtnl deadlocks and race conditions v4
Date: Fri, 26 Feb 2021 07:48:17 -0800	[thread overview]
Message-ID: <20210226074817.7e9e0a71@hermes.local> (raw)
In-Reply-To: <CAF+s_Fx54vCh5dR-HGGmBZVbOHZkAez+aW4W74KBMC62qp2VTg@mail.gmail.com>

On Fri, 26 Feb 2021 00:01:01 +0300
Igor Ryzhov <iryzhov@nfware.com> wrote:

> Hi Elad,
> 
> Thanks for the patch, but this is still NACK from me.
> 
> The only real advantage of KNI over other exceptional-path techniques
> like virtio-user is the ability to configure DPDK-managed interfaces
> directly
> from the kernel using well-known utils like iproute2. A very important part
> of this is getting responses from the DPDK app and knowing the actual
> result of command execution.
> If you're making async requests to the application and you don't know
> the result, then what's the point of using KNI at all?
> 
> Igor

Do you have a better proposal that keeps the request result but does not
call userspace with lock held.

PS: I also have strong dislike of KNI, as designed it would have been rejected
by Linux kernel developers.  A better solution would be userspace version of
something like devlink devices. But doing control operations by proxy is
a locking nightmare.

  reply	other threads:[~2021-02-26 15:49 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-26 14:46 [dpdk-dev] [PATCH] kni: fix rtnl deadlocks and race conditions Elad Nachman
2021-02-19 18:41 ` Ferruh Yigit
2021-02-21  8:03   ` Elad Nachman
2021-02-22 15:58     ` Ferruh Yigit
2021-02-23 12:05 ` [dpdk-dev] [PATCH V2] kni: fix rtnl deadlocks and race conditions v2 Elad Nachman
2021-02-23 12:53   ` Ferruh Yigit
2021-02-23 13:44 ` [dpdk-dev] [PATCH 1/2] kni: fix rtnl deadlocks and race conditions v3 Elad Nachman
2021-02-23 13:45 ` [dpdk-dev] [PATCH 2/2] " Elad Nachman
2021-02-24 12:49   ` Igor Ryzhov
2021-02-24 13:33     ` Elad Nachman
2021-02-24 14:04       ` Igor Ryzhov
2021-02-24 14:06         ` Elad Nachman
2021-02-24 14:41           ` Igor Ryzhov
2021-02-24 14:56             ` Elad Nachman
2021-02-24 15:18               ` Igor Ryzhov
     [not found]                 ` <CACXF7qkhkzFc-=v=iiBzh2V7rLjk1U34VUfPbNrnYJND_0TKHQ@mail.gmail.com>
2021-02-24 16:31                   ` Igor Ryzhov
2021-02-24 15:54     ` Stephen Hemminger
2021-02-25 14:32 ` [dpdk-dev] [PATCH 1/2] kni: fix kernel deadlock when using mlx devices Elad Nachman
2021-02-25 14:32   ` [dpdk-dev] [PATCH 2/2] kni: fix rtnl deadlocks and race conditions v4 Elad Nachman
2021-02-25 21:01     ` Igor Ryzhov
2021-02-26 15:48       ` Stephen Hemminger [this message]
2021-02-26 17:43         ` Elad Nachman
2021-03-01  8:10           ` Igor Ryzhov
2021-03-01 16:38             ` Stephen Hemminger
2021-03-15 16:58               ` Ferruh Yigit
2021-03-01 20:27             ` Dan Gora
2021-03-01 21:26               ` Dan Gora
2021-03-02 16:44                 ` Elad Nachman
2021-03-15 17:17     ` Ferruh Yigit
2021-03-16 18:35       ` Elad Nachman
2021-03-16 18:42         ` Ferruh Yigit
2021-03-15 17:17   ` [dpdk-dev] [PATCH 1/2] kni: fix kernel deadlock when using mlx devices Ferruh Yigit
2021-03-29 14:36 ` [dpdk-dev] [PATCH v5 1/3] kni: refactor user request processing Ferruh Yigit
2021-03-29 14:36   ` [dpdk-dev] [PATCH v5 2/3] kni: support async user request Ferruh Yigit
2021-03-29 14:36   ` [dpdk-dev] [PATCH v5 3/3] kni: fix kernel deadlock when using mlx devices Ferruh Yigit
2021-04-09 14:56     ` [dpdk-dev] [dpdk-stable] " Ferruh Yigit
2021-04-12 14:35       ` Elad Nachman
2021-04-20 23:07         ` Thomas Monjalon
2021-04-23  8:41           ` Igor Ryzhov
2021-04-23  8:59             ` Ferruh Yigit
2021-04-23 12:43               ` Igor Ryzhov
2021-04-23 12:58                 ` Igor Ryzhov

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