From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Blumenstingl Subject: Re: [v3, net-next, 02/12] net: stmmac: Do not keep rearming the coalesce timer in stmmac_xmit Date: Thu, 23 Aug 2018 20:42:12 +0200 Message-ID: References: <9d0be5db11478d00a9194065abcf137b4d537c0a.1526651009.git.joabreu@synopsys.com> <7c15f9477adbf69c6eb57a2a89273f7afc51574e.camel@baylibre.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: netdev@vger.kernel.org, linux-amlogic@lists.infradead.org, khilman@baylibre.com, bgolaszewski@baylibre.com, davem@davemloft.net To: jbrunet@baylibre.com, Jose.Abreu@synopsys.com, peppe.cavallaro@st.com, Joao.Pinto@synopsys.com, alexandre.torgue@st.com, Vitor.Soares@synopsys.com Return-path: Received: from mail-oi0-f67.google.com ([209.85.218.67]:41614 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727135AbeHWWNW (ORCPT ); Thu, 23 Aug 2018 18:13:22 -0400 Received: by mail-oi0-f67.google.com with SMTP id k12-v6so11018005oiw.8 for ; Thu, 23 Aug 2018 11:42:23 -0700 (PDT) In-Reply-To: <7c15f9477adbf69c6eb57a2a89273f7afc51574e.camel@baylibre.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi, On Fri, Aug 17, 2018 at 9:32 AM Jerome Brunet wrote: > > On Fri, 2018-05-18 at 14:55 +0100, Jose Abreu wrote: > > This is cutting down performance. Once the timer is armed it should run > > after the time expires for the first packet sent and not the last one. > > > > After this change, running iperf, the performance gain is +/- 24%. > > Hi Guys, > > Since v4.18, we are getting a serious regression on Amlogic based SoCs. > I have tested this on amlogic's: > * gxbb S905 p200 (Micrel KSZ9031 - 1GBps) > * axg A113 s400 (Realtek RTL8211F - 1GBps) > > Both SoCs use the synopsys gmac with stmmac driver. I can confirm this on Odroid-C1 (Meson8b SoC with RTL8211F RGMII PHY) as well > I first noticed that running NFS root filesystem became unstable but I could not > understand why. Then, running a download as simple test with iperf3 (from an > initramfs) will break the 'network' in matter of seconds. I didn't run iperf, simply downloading the latest rootfs package updates (on Arch Linux ARM) caused the network to break > I don't know exactly what breaks but bisect clearly assign the blame to this > change. Reverting the change solve this problem. > > I'll be happy to make more tests to help understand what is happening here. if some latency is fine then I can also help testing here's a bootlog excerpt with the info from the dwmac-meson8b driver (used on all platforms listed above): meson8b-dwmac c9410000.ethernet: PTP uses main clock meson8b-dwmac c9410000.ethernet: User ID: 0x10, Synopsys ID: 0x37 meson8b-dwmac c9410000.ethernet: DWMAC1000 meson8b-dwmac c9410000.ethernet: DMA HW capability register supported meson8b-dwmac c9410000.ethernet: RX Checksum Offload Engine supported meson8b-dwmac c9410000.ethernet: COE Type 2 meson8b-dwmac c9410000.ethernet: TX Checksum insertion supported meson8b-dwmac c9410000.ethernet: Wake-Up On Lan supported meson8b-dwmac c9410000.ethernet: Normal descriptors meson8b-dwmac c9410000.ethernet: Ring mode enabled meson8b-dwmac c9410000.ethernet: Enable RX Mitigation via HW Watchdog Timer ... meson8b-dwmac c9410000.ethernet eth0: device MAC address [...random mac address...] RTL8211F Gigabit Ethernet stmmac-0:00: attached PHY driver [RTL8211F Gigabit Ethernet] (mii_bus:phy_addr=stmmac-0:00, irq=27) ... meson8b-dwmac c9410000.ethernet eth0: No Safety Features support found meson8b-dwmac c9410000.ethernet eth0: PTP not supported by HW IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready Regards Martin From mboxrd@z Thu Jan 1 00:00:00 1970 From: martin.blumenstingl@googlemail.com (Martin Blumenstingl) Date: Thu, 23 Aug 2018 20:42:12 +0200 Subject: [v3, net-next, 02/12] net: stmmac: Do not keep rearming the coalesce timer in stmmac_xmit In-Reply-To: <7c15f9477adbf69c6eb57a2a89273f7afc51574e.camel@baylibre.com> References: <9d0be5db11478d00a9194065abcf137b4d537c0a.1526651009.git.joabreu@synopsys.com> <7c15f9477adbf69c6eb57a2a89273f7afc51574e.camel@baylibre.com> Message-ID: To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org Hi, On Fri, Aug 17, 2018 at 9:32 AM Jerome Brunet wrote: > > On Fri, 2018-05-18 at 14:55 +0100, Jose Abreu wrote: > > This is cutting down performance. Once the timer is armed it should run > > after the time expires for the first packet sent and not the last one. > > > > After this change, running iperf, the performance gain is +/- 24%. > > Hi Guys, > > Since v4.18, we are getting a serious regression on Amlogic based SoCs. > I have tested this on amlogic's: > * gxbb S905 p200 (Micrel KSZ9031 - 1GBps) > * axg A113 s400 (Realtek RTL8211F - 1GBps) > > Both SoCs use the synopsys gmac with stmmac driver. I can confirm this on Odroid-C1 (Meson8b SoC with RTL8211F RGMII PHY) as well > I first noticed that running NFS root filesystem became unstable but I could not > understand why. Then, running a download as simple test with iperf3 (from an > initramfs) will break the 'network' in matter of seconds. I didn't run iperf, simply downloading the latest rootfs package updates (on Arch Linux ARM) caused the network to break > I don't know exactly what breaks but bisect clearly assign the blame to this > change. Reverting the change solve this problem. > > I'll be happy to make more tests to help understand what is happening here. if some latency is fine then I can also help testing here's a bootlog excerpt with the info from the dwmac-meson8b driver (used on all platforms listed above): meson8b-dwmac c9410000.ethernet: PTP uses main clock meson8b-dwmac c9410000.ethernet: User ID: 0x10, Synopsys ID: 0x37 meson8b-dwmac c9410000.ethernet: DWMAC1000 meson8b-dwmac c9410000.ethernet: DMA HW capability register supported meson8b-dwmac c9410000.ethernet: RX Checksum Offload Engine supported meson8b-dwmac c9410000.ethernet: COE Type 2 meson8b-dwmac c9410000.ethernet: TX Checksum insertion supported meson8b-dwmac c9410000.ethernet: Wake-Up On Lan supported meson8b-dwmac c9410000.ethernet: Normal descriptors meson8b-dwmac c9410000.ethernet: Ring mode enabled meson8b-dwmac c9410000.ethernet: Enable RX Mitigation via HW Watchdog Timer ... meson8b-dwmac c9410000.ethernet eth0: device MAC address [...random mac address...] RTL8211F Gigabit Ethernet stmmac-0:00: attached PHY driver [RTL8211F Gigabit Ethernet] (mii_bus:phy_addr=stmmac-0:00, irq=27) ... meson8b-dwmac c9410000.ethernet eth0: No Safety Features support found meson8b-dwmac c9410000.ethernet eth0: PTP not supported by HW IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready Regards Martin