On Tue, Sep 7, 2021 at 12:11 AM Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote: > > On 06.09.2021 17:10, Kai-Heng Feng wrote: > > On Sat, Sep 4, 2021 at 4:00 AM Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote: > >> > >> On 03.09.2021 17:56, Kai-Heng Feng wrote: > >>> On Tue, Aug 31, 2021 at 2:09 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > >>>> > >>>> On Sat, Aug 28, 2021 at 01:14:52AM +0800, Kai-Heng Feng wrote: > >>>>> r8169 NICs on some platforms have abysmal speed when ASPM is enabled. > >>>>> Same issue can be observed with older vendor drivers. > >>>>> > >>>>> The issue is however solved by the latest vendor driver. There's a new > >>>>> mechanism, which disables r8169's internal ASPM when the NIC traffic has > >>>>> more than 10 packets, and vice versa. The possible reason for this is > >>>>> likely because the buffer on the chip is too small for its ASPM exit > >>>>> latency. > >>>> > >>>> This sounds like good speculation, but of course, it would be better > >>>> to have the supporting data. > >>>> > >>>> You say above that this problem affects r8169 on "some platforms." I > >>>> infer that ASPM works fine on other platforms. It would be extremely > >>>> interesting to have some data on both classes, e.g., "lspci -vv" > >>>> output for the entire system. > >>> > >>> lspci data collected from working and non-working system can be found here: > >>> https://bugzilla.kernel.org/show_bug.cgi?id=214307 > >>> > >>>> > >>>> If r8169 ASPM works well on some systems, we *should* be able to make > >>>> it work well on *all* systems, because the device can't tell what > >>>> system it's in. All the device can see are the latencies for entry > >>>> and exit for link states. > >>> > >>> That's definitely better if we can make r8169 ASPM work for all platforms. > >>> > >>>> > >>>> IIUC this patch makes the driver wake up every 1000ms. If the NIC has > >>>> sent or received more than 10 packets in the last 1000ms, it disables > >>>> ASPM; otherwise it enables ASPM. > >>> > >>> Yes, that's correct. > >>> > >>>> > >>>> I asked these same questions earlier, but nothing changed, so I won't > >>>> raise them again if you don't think they're pertinent. Some patch > >>>> splitting comments below. > >>> > >>> Sorry about that. The lspci data is attached. > >>> > >> > >> Thanks for the additional details. I see that both systems have the L1 > >> sub-states active. Do you also face the issue if L1 is enabled but > >> L1.2 and L1.2 are not? Setting the ASPM policy from powersupersave > >> to powersave should be sufficient to disable them. > >> I have a test system Asus PRIME H310I-PLUS, BIOS 2603 10/21/2019 with > >> the same RTL8168h chip version. With L1 active and sub-states inactive > >> everything is fine. With the sub-states activated I get few missed RX > >> errors when running iperf3. > > > > Once L1.1 and L1.2 are disabled the TX speed can reach 710Mbps and RX > > can reach 941 Mbps. So yes it seems to be the same issue. > > I reach 940-950Mbps in both directions, but this seems to be unrelated > to what we discuss here. OK. Is there anything more I need to address in next iteration? Kai-Heng > > > With dynamic ASPM, TX can reach 750 Mbps while ASPM L1.1 and L1.2 are enabled. > > > >> One difference between your good and bad logs is the following. > >> (My test system shows the same LTR value like your bad system.) > >> > >> Bad: > >> Capabilities: [170 v1] Latency Tolerance Reporting > >> Max snoop latency: 3145728ns > >> Max no snoop latency: 3145728ns > >> > >> Good: > >> Capabilities: [170 v1] Latency Tolerance Reporting > >> Max snoop latency: 1048576ns > >> Max no snoop latency: 1048576ns > >> > >> I have to admit that I'm not familiar with LTR and don't know whether > >> this difference could contribute to the differing behavior. > > > > I am also unsure what role LTR plays here, so I tried to change the > > LTR value to 1048576ns and yield the same result, the TX and RX remain > > very slow. > > > > Kai-Heng > > >
