Re: [PATCH mlx5-next v7 0/4] Dynamically assign MSI-X vectors count

From: Leon Romanovsky <leon@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <helgaas@kernel.org>,
	Alexander Duyck <alexander.duyck@gmail.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Saeed Mahameed <saeedm@nvidia.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>,
	linux-rdma@vger.kernel.org, Netdev <netdev@vger.kernel.org>,
	Don Dutile <ddutile@redhat.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH mlx5-next v7 0/4] Dynamically assign MSI-X vectors count
Date: Thu, 11 Mar 2021 10:37:03 +0200	[thread overview]
Message-ID: <YEnWr/xufSXvszIw@unreal> (raw)
In-Reply-To: <YEkqY5ZJLXp8dork@kroah.com>

On Wed, Mar 10, 2021 at 09:21:55PM +0100, Greg Kroah-Hartman wrote:
> On Wed, Mar 10, 2021 at 10:10:41PM +0200, Leon Romanovsky wrote:
> > On Wed, Mar 10, 2021 at 01:09:06PM -0600, Bjorn Helgaas wrote:
> > > On Sun, Mar 07, 2021 at 10:55:24AM -0800, Alexander Duyck wrote:
> > > > On Sun, Feb 28, 2021 at 11:55 PM Leon Romanovsky <leon@kernel.org> wrote:
> > > > > From: Leon Romanovsky <leonro@nvidia.com>
> > > > >
> > > > > @Alexander Duyck, please update me if I can add your ROB tag again
> > > > > to the series, because you liked v6 more.
> > > > >
> > > > > Thanks
> > > > >
> > > > > ---------------------------------------------------------------------------------
> > > > > Changelog
> > > > > v7:
> > > > >  * Rebase on top v5.12-rc1
> > > > >  * More english fixes
> > > > >  * Returned to static sysfs creation model as was implemented in v0/v1.
> >
> > <...>
> >
> > >   2) Should a VF sysfs file use the PF to implement this?
> > >
> > >      Can you elaborate on your idea here?  I guess
> > >      pci_iov_sysfs_link() makes a "virtfnX" link from the PF to the
> > >      VF, and you're thinking we could also make a "virtfnX_msix_count"
> > >      in the PF directory?  That's a really interesting idea.
> >
> > I want to remind that we are talking about mlx5 devices that support
> > upto 255 VFs and they indeed are used to their limits. So seeing 255
> > links of virtfnX_msix_count in the same directory looks too much unpleasant
> > to me.
>
> 255 files are nothing, if that's what the hardware supports, what is the
> problem?  If it's "unpleasant", go complain to the hardware designers :)

It is 255 same files that every SR-IOV user will see in /sys/bus/pci/devices/*/
folder, unless we will do dynamic creation of those files and this is something
that Bjorn didn't like in v7.

So instead of complaining to the hardware designers, I will complain here.
I probably implemented all possible variants already. :)

Thanks

>
> greg k-h