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From: Stephen Hemminger <stephen@networkplumber.org>
To: Matan Azrad <matan@nvidia.com>
Cc: "matan@mellanox.com" <matan@mellanox.com>,
	"grive@u246.net" <grive@u246.net>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] net/vdev_netvsc: handle removal of associated pci device
Date: Sun, 6 Sep 2020 11:33:09 -0700	[thread overview]
Message-ID: <20200906113309.4a320400@hermes.lan> (raw)
In-Reply-To: <MW2PR12MB2492D5F88DF930BC0EA188DDDF2B0@MW2PR12MB2492.namprd12.prod.outlook.com>

On Sun, 6 Sep 2020 12:38:18 +0000
Matan Azrad <matan@nvidia.com> wrote:

> Hi Stephen
> 
> From: Stephen Hemminger:
> > The vdev_netvsc was not detecting when the associated PCI device
> > (SRIOV) was removed. Because of that it would keep feeding the same
> > (removed) device to failsafe PMD which would then unsuccessfully try and
> > probe for it.
> > 
> > Change to use a mark/sweep method to detect that PCI device was
> > removed, and also only tell failsafe about new PCI devices.
> > Vdev_netvsc does not have to keep stuffing the pipe with the same already
> > existing PCI device.  
> 
> As I know, the vdev_netvsc driver doesn't call to failsafe if the PCI device is not detected by the readlink command(considered as removed)...
> Am I missing something?

The original code is broken because ctx_yield is not cleared, it keeps sending the same value.
It looks like device removal and add was never tested.

If you test removal you will see that vdev_netvsc:
 1. Sends same PCI device repeatedly to failsafe (every alarm call)
    This is harmless, but useless.
 2. When device is removed, keeps doing #1

  reply	other threads:[~2020-09-06 18:33 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-19 17:53 Stephen Hemminger
2020-09-06  8:11 ` Long Li
2020-09-06 12:38 ` Matan Azrad
2020-09-06 18:33   ` Stephen Hemminger [this message]
2020-09-07  8:09     ` Matan Azrad
2020-09-15  4:53       ` Long Li
2020-09-15  7:00         ` Matan Azrad
2020-09-25 20:30           ` Long Li
2020-10-19 22:33             ` Thomas Monjalon
2020-10-19 22:36               ` Thomas Monjalon
2020-10-20  9:13                 ` Gaëtan Rivet

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