From mboxrd@z Thu Jan 1 00:00:00 1970 From: Giuseppe CAVALLARO Subject: [net-next.git 0/7] stmmac: remove dead code for STMMAC_TIMER and add new mitigation schema. Date: Mon, 3 Sep 2012 09:46:55 +0200 Message-ID: <1346658422-1925-1-git-send-email-peppe.cavallaro@st.com> Cc: Giuseppe Cavallaro To: netdev@vger.kernel.org Return-path: Received: from eu1sys200aog101.obsmtp.com ([207.126.144.111]:35834 "EHLO eu1sys200aog101.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753016Ab2ICHrM (ORCPT ); Mon, 3 Sep 2012 03:47:12 -0400 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 577B21E3 for ; Mon, 3 Sep 2012 07:47:07 +0000 (GMT) Received: from mail7.sgp.st.com (mail7.sgp.st.com [164.129.223.81]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id D241A2B9C for ; Mon, 3 Sep 2012 07:47:07 +0000 (GMT) Sender: netdev-owner@vger.kernel.org List-ID: These patch series remove the STMMAC_TIMER option no longer updated and never used and add a new mitigation schema. Having removed the Timer opt, this has made the driver slim. On top of this work, it has been easier to introduce the new mitigation schema based on HW RX-watchdog (available in new cores). In fact, 3.50 and newer cores have an HW RX-Watchdog that can be used for mitigating the Rx-interrupts and first results look promising. Running n-u-t-t-c-p with the following parameters: Throughput: 500Mbps UDP Buffer size: 1328bytes TCP Buffer size: 65536bytes for example, I got on ST box (arm-based) these improvements: -------------------------------------------------------------------- Original | With New Mitigation patch -------------------------------------------------------------------- Test CPU usage pkt/loss | CPU usage pkt/loss Type Mbps % % |Mbps % % -------------------------------------------------------------------- UDP-RX 395.5065 95 20.89 |499.9966 25 0.00% UDP-TX 499.5578 100 0.08915 |499.7156 100 0.06029% TCP-RX 499.9221 77 |499.8648 41 TCP-TX 389.5719 99 |499.2802 79 -------------------------------------------------------------------- ... no regression on ST boxes (SH based) I always test. This is a brief explanation of the new mitigation schema although there is a patch that updates the driver's documentation. o On Rx-side I have: New GMACs will use the RX-watchdog timer; old ones will continue to use NAPI to mitigate the RX DMA interrupts. For the RX-watchdog, there is a parameter that is the RI Watchdog Timer count. It indicates the number of system clock cycles and can be set via sysFS. Next step will be to tune it via ethtool. o On Tx-side, the mitigation schema is based on a SW timer that calls the tx function (stmmac_tx) to reclaim the resource after transmitting the frames. Also there is another parameter (a threshold) used to program the descriptors avoiding to set the interrupt on completion bit in when the frame is sent (xmit). This means that the stmmac_tx can be called by the ISR too. Also this parameter can be tuned via sysFs and not yet via ethtool. Note1: there is a patch that updates the driver to August 2012. I hope to also release the PTP support and update the driver in the next weeks. Note2: next step will be to tune coalesce params via ethtool. I'll do that. peppe Giuseppe Cavallaro (7): stmmac: remove dead code for TIMER stmmac: manage tx clean out of rx_poll stmmac: add the initial tx coalesce schema stmmac: add Rx watchdog optimization to mitigate the DMA irqs stmmac: add sysFs support stmmac: add mitigation and sysfs info in the doc stmmac: update the driver version to August_2012 Documentation/networking/stmmac.txt | 34 ++- drivers/net/ethernet/stmicro/stmmac/Kconfig | 25 -- drivers/net/ethernet/stmicro/stmmac/Makefile | 3 +- drivers/net/ethernet/stmicro/stmmac/common.h | 30 ++- drivers/net/ethernet/stmicro/stmmac/dwmac1000.h | 3 - .../net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 6 + drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h | 3 +- drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c | 7 +- drivers/net/ethernet/stmicro/stmmac/stmmac-sysfs.c | 157 +++++++++++ drivers/net/ethernet/stmicro/stmmac/stmmac.h | 15 +- .../net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 9 +- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 282 +++++++++----------- drivers/net/ethernet/stmicro/stmmac/stmmac_timer.c | 134 --------- drivers/net/ethernet/stmicro/stmmac/stmmac_timer.h | 46 ---- 14 files changed, 354 insertions(+), 400 deletions(-) create mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac-sysfs.c delete mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_timer.c delete mode 100644 drivers/net/ethernet/stmicro/stmmac/stmmac_timer.h -- 1.7.4.4