netdev - Re: [net-next V2 08/15] net/mlx5e: Add TX PTP port object support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20201207122907.359796c0@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com>
Date:   Mon, 7 Dec 2020 12:29:07 -0800
From:   Jakub Kicinski <kuba@...nel.org>
To:     Eran Ben Elisha <eranbe@...dia.com>
Cc:     Saeed Mahameed <saeed@...nel.org>,
        "David S. Miller" <davem@...emloft.net>, <netdev@...r.kernel.org>,
        "Tariq Toukan" <tariqt@...dia.com>
Subject: Re: [net-next V2 08/15] net/mlx5e: Add TX PTP port object support

On Sun, 6 Dec 2020 15:36:38 +0200 Eran Ben Elisha wrote:
> On 12/5/2020 1:17 AM, Jakub Kicinski wrote:
> >> We only forward ptp traffic to the new special queue but we create more
> >> than one to avoid internal locking as we will utilize the tx softirq
> >> percpu.  
> > In other words to make the driver implementation simpler we'll have
> > a pretty basic feature hidden behind a ethtool priv knob and a number
> > of queues which doesn't match reality reported to user space. Hm.  
> 
> We are not hiding these queues from the netdev stack. We report them in 
> real num of TX queues and manage them as any other queue. The only 
> change is that select_queue() will select a stream to them if and only 
> if they match specific criteria.

Please read more carefully what you're replying to. That helps
communication and limits frustration quite a lot.

I said the queues are hidden behind the ethtool knob, as in they are
only instantiated when knob is turned from its default position.
Then you report to the stack that you have n+m queues, but in fact
there is only n queues that are of general use.