[dpdk-dev] [PATCH v2 2/2] net/i40e: add hot plug monitor in i40e

[Guo, Jia]

Agree with jingjing.

That patch is definitely not for generic fashion of hot plug,  the uevent just give the adding  approach to monitor the remove event even if the driver not add it as interrupt , we know mlx driver have already implement the event of remove interrupt into their infinite framework driver, but other driver maybe not yet.
So uevent is not unique for i40e or other intel nic, the aim just let more diversity drivers which use pci-uio framework  to use the common hot plug feature in DPDK.

Best regards,
Jeff Guo


-----Original Message-----
From: Wu, Jingjing 
Sent: Thursday, June 29, 2017 12:48 PM
To: Stephen Hemminger <stephen at networkplumber.org>; Guo, Jia <jia.guo at intel.com>
Cc: Zhang, Helin <helin.zhang at intel.com>; dev at dpdk.org; Chang, Cunyin <cunyin.chang at intel.com>; Liang, Cunming <cunming.liang at intel.com>
Subject: RE: [dpdk-dev] [PATCH v2 2/2] net/i40e: add hot plug monitor in i40e



> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Thursday, June 29, 2017 11:35 AM
> To: Guo, Jia <jia.guo at intel.com>
> Cc: Zhang, Helin <helin.zhang at intel.com>; Wu, Jingjing 
> <jingjing.wu at intel.com>; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v2 2/2] net/i40e: add hot plug monitor 
> in i40e
> 
> On Wed, 28 Jun 2017 19:07:24 +0800
> Jeff Guo <jia.guo at intel.com> wrote:
> 
> > From: "Guo, Jia" <jia.guo at intel.com>
> >
> > This patch enable the hot plug feature in i40e, by monitoring the 
> > hot plug uevent of the device. When remove event got, call the app 
> > callback function to handle the detach process.
> >
> > Signed-off-by: Guo, Jia <jia.guo at intel.com>
> > ---
> 
> Hot plug is good and needed.
> 
> But it needs to be done in a generic fashion in the bus layer.
> There is nothing about uevents that are unique to i40e or even Intel devices.
> Plus the way hotplug is handled is OS specific, so this isn't going to 
> work well on BSD.
> 
This patch is not a way to full support hut plug. And we know it is handled in OS specific.
This patch just provides a way to tell DPDK user the remove happened on this device (DPDK dev).

And Mlx driver already supports that with patch http://dpdk.org/dev/patchwork/patch/23695/

What GuoJia did is just making the EVENT can be process by application through interrupt callback Mechanisms.

> Sorry if I sound like a broken record but there has been a repeated 
> pattern of Intel developers  putting their head down (or in the sand) 
> and creating functionality inside device driver.
Sorry, I cannot agree.

Thanks
Jingjing