From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinicius Costa Gomes Date: Tue, 19 May 2020 08:32:40 -0700 Subject: [Intel-wired-lan] [next-queue RFC 0/4] ethtool: Add support for frame preemption In-Reply-To: References: <20200516012948.3173993-1-vinicius.gomes@intel.com> Message-ID: <87v9ksndnr.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: Murali Karicheri writes: >> $ ethtool $ sudo ./ethtool --show-frame-preemption enp3s0 >> Frame preemption settings for enp3s0: >> support: supported >> active: active >> supported queues: 0xf > > I assume this is will be in sync with ethtool -L output which indicates > how many tx h/w queues present? I mean if there are 8 h/w queues, > supported queues will show 0xff. In this approach, the driver builds these bitmasks, so it's responsible to keep it consistent with the rest of the stuff that's exposed in ethtool. > >> supported queues: 0xe > From the command below, it appears this is the preemptible queue mask. > bit 0 is Q0, bit 1 Q1 and so forth. Right? In that case isn't it more > clear to display > preemptible queues : 0xef > > In the above Q7 is express queue and Q6-Q0 are preemptible. In my case, the controller I have here only has 4 queues, and Queue 0 is the highest priority one, and it's marked as express. > > Also there is a handshake called verify that happens which initiated > by the h/w to check the capability of peer. It looks like > not all vendor's hardware supports it and good to have it displayed > something like > > Verify supported/{not supported} > > If Verify is supported, FPE is enabled only if it succeeds. So may be > good to show a status of Verify if it is supported something like > Verify success/Failed > >> minimum fragment size: 68 >> >> >> $ ethtool --set-frame-preemption enp3s0 fp on min-frag-size 68 preemptible-queues-mask 0xe >> >> This is a RFC because I wanted to have feedback on some points: >> >> - The parameters added are enough for the hardware I have, is it >> enough in general? > > As described above, it would be good to add an optional parameter for > verify > > ethtool --set-frame-preemption enp3s0 fp on min-frag-size 68 > preemptible-queues-mask 0xe verify on > The hardware I have do not support this, but this makes sense. Cheers, -- Vinicius