From patchwork Wed Oct 18 12:35:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Marangi X-Patchwork-Id: 736194 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10E86CDB483 for ; Wed, 18 Oct 2023 12:36:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344652AbjJRMgE (ORCPT ); Wed, 18 Oct 2023 08:36:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234927AbjJRMgC (ORCPT ); Wed, 18 Oct 2023 08:36:02 -0400 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AC35114; Wed, 18 Oct 2023 05:36:00 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-4083cd39188so4660215e9.2; Wed, 18 Oct 2023 05:36:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697632558; x=1698237358; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=0v0ZmldTmEHElH0nzfPoImpxhHxc/jfxnYXGlHkEaSw=; b=P/FnAP9ANfmDDxex6pXE8sdpnuIA4RjlogwtL6Ul37mnpF5bcN8VE6D1bXHGPoU/OC XPpRFIMlnIOzYWN9j2OU0uqXtjcRwG7gNyQqdIkstfJs2yS77OGXs1gJlPfSwdQ61o24 JUGwhY8GK9AtKTosNTe5c2gD0y5wTekNzzRLKQjEgsLEd0dKBgRlN0Szp9tyV4IXTqHG bdtJwW+YKtP4YeEoA7v5khVhlS12LQG0ELO+kLVXCANJyWW44L8dMHL6uZbM7nLYVLvR ZL+kwYh8I84WS9ed2GWAlAZFr782nQrj5p9WlP7rRa99+1Is/0ptvQqyOao4PrQyt0Ne PrzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697632558; x=1698237358; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=0v0ZmldTmEHElH0nzfPoImpxhHxc/jfxnYXGlHkEaSw=; b=Ls/g2JXAAXVTqVAt3lnqRZZMMjtBZ7MXNOq59r+ZUbnaRlsnCF4tsyLqJxQYOo8Gkt E5BaZDV4/Iye9ss41ZVqLpwJEBKwoV8JbKqY1oRXn9M9EZRPGjE6E3sDfpxKSAjR/Sbp Qab6QlRUcTTxaOASJDygBW6OEanyNqzPMvJ+40s7fM0XZA4LSFBdhhlTwneoyhj4xR8m 15eramOofmJouBpxd/yyyBJXykAH/2pPvI3X1l/2Ucbc6DCb2AS6MVabUV1Srasot1st iP+fQDCNiXF8OE/lOvJNrC9BbCLeR84yvO/iOLfdebbvgS9E5vBlGdKzk5DFUgyF4O47 QvtQ== X-Gm-Message-State: AOJu0Yy12u167d84IWg6WHdqe6wX6KbJqb+KqzEuLhG4mdvKaPP4mstq /SmkREEnguTtCv5DZBrjoy3qQzEcwrU= X-Google-Smtp-Source: AGHT+IHYxeHjCIR/FT2JDqNfUwmEd2G8A/49wx/hETYLT6M/03g9TnduO1+10bkcfRpmv5Wp7ErFMw== X-Received: by 2002:a05:600c:3511:b0:404:72fe:ed5c with SMTP id h17-20020a05600c351100b0040472feed5cmr4380670wmq.29.1697632558280; Wed, 18 Oct 2023 05:35:58 -0700 (PDT) Received: from localhost.localdomain (93-34-89-13.ip49.fastwebnet.it. [93.34.89.13]) by smtp.googlemail.com with ESMTPSA id q28-20020adfab1c000000b003248a490e3asm2048211wrc.39.2023.10.18.05.35.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 05:35:57 -0700 (PDT) From: Christian Marangi To: Raju Rangoju , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Ping-Ke Shih , Kalle Valo , Simon Horman , Daniel Borkmann , Jiri Pirko , Hangbin Liu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-wireless@vger.kernel.org Cc: Christian Marangi Subject: [net-next PATCH v4 1/4] net: introduce napi_is_scheduled helper Date: Wed, 18 Oct 2023 14:35:47 +0200 Message-Id: <20231018123550.27110-2-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231018123550.27110-1-ansuelsmth@gmail.com> References: <20231018123550.27110-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org We currently have napi_if_scheduled_mark_missed that can be used to check if napi is scheduled but that does more thing than simply checking it and return a bool. Some driver already implement custom function to check if napi is scheduled. Drop these custom function and introduce napi_is_scheduled that simply check if napi is scheduled atomically. Update any driver and code that implement a similar check and instead use this new helper. Signed-off-by: Christian Marangi --- drivers/net/ethernet/chelsio/cxgb3/sge.c | 8 -------- drivers/net/wireless/realtek/rtw89/core.c | 2 +- include/linux/netdevice.h | 23 +++++++++++++++++++++++ net/core/dev.c | 2 +- 4 files changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c b/drivers/net/ethernet/chelsio/cxgb3/sge.c index 2e9a74fe0970..71fa2dc19034 100644 --- a/drivers/net/ethernet/chelsio/cxgb3/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c @@ -2501,14 +2501,6 @@ static int napi_rx_handler(struct napi_struct *napi, int budget) return work_done; } -/* - * Returns true if the device is already scheduled for polling. - */ -static inline int napi_is_scheduled(struct napi_struct *napi) -{ - return test_bit(NAPI_STATE_SCHED, &napi->state); -} - /** * process_pure_responses - process pure responses from a response queue * @adap: the adapter diff --git a/drivers/net/wireless/realtek/rtw89/core.c b/drivers/net/wireless/realtek/rtw89/core.c index cca18d7ea1dd..6faf4dcf007c 100644 --- a/drivers/net/wireless/realtek/rtw89/core.c +++ b/drivers/net/wireless/realtek/rtw89/core.c @@ -1919,7 +1919,7 @@ static void rtw89_core_rx_to_mac80211(struct rtw89_dev *rtwdev, struct napi_struct *napi = &rtwdev->napi; /* In low power mode, napi isn't scheduled. Receive it to netif. */ - if (unlikely(!test_bit(NAPI_STATE_SCHED, &napi->state))) + if (unlikely(!napi_is_scheduled(napi))) napi = NULL; rtw89_core_hw_to_sband_rate(rx_status); diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 1c7681263d30..b8bf669212cc 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -482,6 +482,29 @@ static inline bool napi_prefer_busy_poll(struct napi_struct *n) return test_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state); } +/** + * napi_is_scheduled - test if NAPI is scheduled + * @n: NAPI context + * + * This check is "best-effort". With no locking implemented, + * a NAPI can be scheduled or terminate right after this check + * and produce not precise results. + * + * NAPI_STATE_SCHED is an internal state, napi_is_scheduled + * should not be used normally and napi_schedule should be + * used instead. + * + * Use only if the driver really needs to check if a NAPI + * is scheduled for example in the context of delayed timer + * that can be skipped if a NAPI is already scheduled. + * + * Return True if NAPI is scheduled, False otherwise. + */ +static inline bool napi_is_scheduled(struct napi_struct *n) +{ + return test_bit(NAPI_STATE_SCHED, &n->state); +} + bool napi_schedule_prep(struct napi_struct *n); /** diff --git a/net/core/dev.c b/net/core/dev.c index 3ca746a5f0ad..8d267fc0b988 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6527,7 +6527,7 @@ static int __napi_poll(struct napi_struct *n, bool *repoll) * accidentally calling ->poll() when NAPI is not scheduled. */ work = 0; - if (test_bit(NAPI_STATE_SCHED, &n->state)) { + if (napi_is_scheduled(n)) { work = n->poll(n, weight); trace_napi_poll(n, work, weight); } From patchwork Wed Oct 18 12:35:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Marangi X-Patchwork-Id: 735510 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E685CDB482 for ; Wed, 18 Oct 2023 12:36:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231804AbjJRMgH (ORCPT ); Wed, 18 Oct 2023 08:36:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344655AbjJRMgE (ORCPT ); Wed, 18 Oct 2023 08:36:04 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E71A113; Wed, 18 Oct 2023 05:36:01 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id ffacd0b85a97d-32daeed7771so2965132f8f.3; Wed, 18 Oct 2023 05:36:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697632560; x=1698237360; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=zIsjeim7XUbQUze6bD56uxG9gvOx0giE5m3S+sNf+CI=; b=NZQ1dopMzs9JBX0+XB3sQ6lqbTyB33OMzYXljCwQ0mYNN9X/zEDi4R3pKmC1ir4L7o 94xs61bTzdulUcu8Gh34TeN2qs9OOikpBvEDeLGVjFK+BoYvPaG0ui1cqKpV0BgB/FuT QPG0AZM3zRKWnRqE7S+v4wIGXzyLiKHyoEisoSIdxOfPz/JuOktzsylDFdUU2fojQ2Qw GCjcbyDNEhG2h36VHbyXSp4/tSVOq30AqHRZzzfRknrjf6jAuNa2HhEeBlteF17g5mR3 F/GFodtliymRE2yN85Rir5yZo0LUU0KBSLTlRis0GS9mDsbg/1w0BjdFZkeXA9v+G2s0 sAiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697632560; x=1698237360; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zIsjeim7XUbQUze6bD56uxG9gvOx0giE5m3S+sNf+CI=; b=lgeabj2bfYukeWNDzVtBTvlqjCY2C3dxdsdxBYotG9yoALmsvBq/naMgQ13pDoHJHs Sw0tqoFYjLEizDof5qc2HAB/U7PyzvjDy06/c1qgVC0QIM644WQske56ac3oQNNNjMm0 tgpUTRDegspBmH7HI/ISicfpOcD022RsgYEZcJhdxbbv3+HG/zlRwSgzQlEeYAcQyvl7 WZLBWJuGz+WwAD+Oh/8TN89Y5LsmjfrKFhFO2bjhFwmECm4AzOuvDYTl0fEm8L30laXz Z5BbG1/fNT6QZAkZDfvxN2T+FFlbrvrRl+62Kiw18tAV1hl0ljNdVeEp9cMX67YzSTJE StZA== X-Gm-Message-State: AOJu0Yxl89f7Eyf9Srpfar38RlABJvD0e1bkbuJS9LjLWBV+z3xrrH3M QhHUmBHpenhbYg6wOqN51D+SPJnLNhQ= X-Google-Smtp-Source: AGHT+IEZ/yWPDm00bOSfruAAtBtiN55X0phfrsbW+b1WslVPJVgBsSSIwAeMQJfpT/HeejohPGGPLA== X-Received: by 2002:adf:e8c6:0:b0:32d:9d6b:ac99 with SMTP id k6-20020adfe8c6000000b0032d9d6bac99mr4372102wrn.31.1697632559722; Wed, 18 Oct 2023 05:35:59 -0700 (PDT) Received: from localhost.localdomain (93-34-89-13.ip49.fastwebnet.it. [93.34.89.13]) by smtp.googlemail.com with ESMTPSA id q28-20020adfab1c000000b003248a490e3asm2048211wrc.39.2023.10.18.05.35.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 05:35:59 -0700 (PDT) From: Christian Marangi To: Raju Rangoju , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Ping-Ke Shih , Kalle Valo , Simon Horman , Daniel Borkmann , Jiri Pirko , Hangbin Liu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-wireless@vger.kernel.org Cc: Christian Marangi Subject: [net-next PATCH v4 2/4] net: stmmac: improve TX timer arm logic Date: Wed, 18 Oct 2023 14:35:48 +0200 Message-Id: <20231018123550.27110-3-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231018123550.27110-1-ansuelsmth@gmail.com> References: <20231018123550.27110-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org There is currently a problem with the TX timer getting armed multiple unnecessary times causing big performance regression on some device that suffer from heavy handling of hrtimer rearm. The use of the TX timer is an old implementation that predates the napi implementation and the interrupt enable/disable handling. Due to stmmac being a very old code, the TX timer was never evaluated again with this new implementation and was kept there causing performance regression. The performance regression started to appear with kernel version 4.19 with 8fce33317023 ("net: stmmac: Rework coalesce timer and fix multi-queue races") where the timer was reduced to 1ms causing it to be armed 40 times more than before. Decreasing the timer made the problem more present and caused the regression in the other of 600-700mbps on some device (regression where this was notice is ipq806x). The problem is in the fact that handling the hrtimer on some target is expensive and recent kernel made the timer armed much more times. A solution that was proposed was reverting the hrtimer change and use mod_timer but such solution would still hide the real problem in the current implementation. To fix the regression, apply some additional logic and skip arming the timer when not needed. Arm the timer ONLY if a napi is not already scheduled. Running the timer is redundant since the same function (stmmac_tx_clean) will run in the napi TX poll. Also try to cancel any timer if a napi is scheduled to prevent redundant run of TX call. With the following new logic the original performance are restored while keeping using the hrtimer. Signed-off-by: Christian Marangi --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index bb1dbf4c9f6c..5124ee87286c 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2996,13 +2996,25 @@ static void stmmac_tx_timer_arm(struct stmmac_priv *priv, u32 queue) { struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue]; u32 tx_coal_timer = priv->tx_coal_timer[queue]; + struct stmmac_channel *ch; + struct napi_struct *napi; if (!tx_coal_timer) return; - hrtimer_start(&tx_q->txtimer, - STMMAC_COAL_TIMER(tx_coal_timer), - HRTIMER_MODE_REL); + ch = &priv->channel[tx_q->queue_index]; + napi = tx_q->xsk_pool ? &ch->rxtx_napi : &ch->tx_napi; + + /* Arm timer only if napi is not already scheduled. + * Try to cancel any timer if napi is scheduled, timer will be armed + * again in the next scheduled napi. + */ + if (unlikely(!napi_is_scheduled(napi))) + hrtimer_start(&tx_q->txtimer, + STMMAC_COAL_TIMER(tx_coal_timer), + HRTIMER_MODE_REL); + else + hrtimer_try_to_cancel(&tx_q->txtimer); } /** From patchwork Wed Oct 18 12:35:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Marangi X-Patchwork-Id: 736193 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C957CDB484 for ; Wed, 18 Oct 2023 12:36:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235169AbjJRMgI (ORCPT ); Wed, 18 Oct 2023 08:36:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48818 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344661AbjJRMgF (ORCPT ); Wed, 18 Oct 2023 08:36:05 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47FCEA3; Wed, 18 Oct 2023 05:36:03 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id 5b1f17b1804b1-405361bb94eso72759545e9.0; Wed, 18 Oct 2023 05:36:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1697632561; x=1698237361; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=fQganKp8aZF21H/zUPTyA0gQtuZNoVrMeBEcku+H04Y=; b=kDBc++rI5D/Q2SPGoKVhEUpexVBs4FZ0JP/6w/LxVJh4Gqm9iLTHU1/L7TWmUvASfS HgQCqU0egYRFX59nBTFK/H9aTAJA+fHQvCuygFwmy5jo/+MVvbBQ2MJ2RfDlc5/p2nZF W7rhIo7vvoesHMTXqBO3P1HtgQN/BVxz9jfG77Ob1HmZeV/gxo2mrwJEHHB9nuKp6t37 kl94IldcHaF0gfTGmKbnhsU+ykzpNQRzW2flhYW0vmOdoS0APbuuaC6cnq4UIyswfRD7 qTo8r7OrkqVEpG7sLIbikLUL26PWJiFr3cW94LypzMCLheHOjOf47xv4WprOX6T9DmBq bDjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697632561; x=1698237361; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=fQganKp8aZF21H/zUPTyA0gQtuZNoVrMeBEcku+H04Y=; b=Ax9y17OVR4wkjREZ/tOreUw9bQa+hJgf6hIsbp+STnKTKTcS/wWjy7Yc7umHRxlCg0 EOkMJ3CIvlkrBIdcJJW+lyLxFiJ77E4ekIJ3cOGVESINXWLrDmsEeZEaRQglBkjFVx5k evjnAkRzRjQSZfQFO7Y7E0gu15xX9cg5YP9dTbwk9LE1NZzhPRFibZTLwkS1sRr4IoSQ 4sSeMRRlfHQn89kABIV+Xz2sPFedm9I/QYqQNK3PxeA/e4ecqhAeq2p0/D9BGsE5eCx5 WhA+JKFU6J7v5BCYNQUR16f2Enme92S+zEVA4ERkCcXyzfxV8Xs2hQugKmHoxuJ3bEnp +NKA== X-Gm-Message-State: AOJu0YwEoVD0XKVCkE+kB82hTstfCUxpf6VGt7lDhAoSapXvzJ3FVl09 K1Dycq9dx6VeSs4bvjQqQBY= X-Google-Smtp-Source: AGHT+IGWvw4ZG3SuGsV3ihR3L7f4r/gBqme7cwP3cF/b5NR29eZ1jaXh9BTqQTHxCvA+LdtfhtVbtA== X-Received: by 2002:adf:cf0e:0:b0:32d:a43c:a23d with SMTP id o14-20020adfcf0e000000b0032da43ca23dmr4654866wrj.3.1697632560973; Wed, 18 Oct 2023 05:36:00 -0700 (PDT) Received: from localhost.localdomain (93-34-89-13.ip49.fastwebnet.it. [93.34.89.13]) by smtp.googlemail.com with ESMTPSA id q28-20020adfab1c000000b003248a490e3asm2048211wrc.39.2023.10.18.05.35.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 05:36:00 -0700 (PDT) From: Christian Marangi To: Raju Rangoju , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Ping-Ke Shih , Kalle Valo , Simon Horman , Daniel Borkmann , Jiri Pirko , Hangbin Liu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-wireless@vger.kernel.org Cc: Christian Marangi Subject: [net-next PATCH v4 3/4] net: stmmac: move TX timer arm after DMA enable Date: Wed, 18 Oct 2023 14:35:49 +0200 Message-Id: <20231018123550.27110-4-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231018123550.27110-1-ansuelsmth@gmail.com> References: <20231018123550.27110-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Move TX timer arm call after DMA interrupt is enabled again. The TX timer arm function changed logic and now is skipped if a napi is already scheduled. By moving the TX timer arm call after DMA is enabled, we permit to correctly skip if a DMA interrupt has been fired and a napi has been scheduled again. Signed-off-by: Christian Marangi --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 22 +++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 5124ee87286c..11055e98efcc 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2543,9 +2543,13 @@ static void stmmac_bump_dma_threshold(struct stmmac_priv *priv, u32 chan) * @priv: driver private structure * @budget: napi budget limiting this functions packet handling * @queue: TX queue index + * @pending_packets: signal to arm the TX coal timer * Description: it reclaims the transmit resources after transmission completes. + * If some packets still needs to be handled, due to TX coalesce, set + * pending_packets to true to make NAPI arm the TX coal timer. */ -static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) +static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue, + bool *pending_packets) { struct stmmac_tx_queue *tx_q = &priv->dma_conf.tx_queue[queue]; struct stmmac_txq_stats *txq_stats = &priv->xstats.txq_stats[queue]; @@ -2706,7 +2710,7 @@ static int stmmac_tx_clean(struct stmmac_priv *priv, int budget, u32 queue) /* We still have pending packets, let's call for a new scheduling */ if (tx_q->dirty_tx != tx_q->cur_tx) - stmmac_tx_timer_arm(priv, queue); + *pending_packets = true; flags = u64_stats_update_begin_irqsave(&txq_stats->syncp); txq_stats->tx_packets += tx_packets; @@ -5572,6 +5576,7 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget) container_of(napi, struct stmmac_channel, tx_napi); struct stmmac_priv *priv = ch->priv_data; struct stmmac_txq_stats *txq_stats; + bool pending_packets = false; u32 chan = ch->index; unsigned long flags; int work_done; @@ -5581,7 +5586,7 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget) txq_stats->napi_poll++; u64_stats_update_end_irqrestore(&txq_stats->syncp, flags); - work_done = stmmac_tx_clean(priv, budget, chan); + work_done = stmmac_tx_clean(priv, budget, chan, &pending_packets); work_done = min(work_done, budget); if (work_done < budget && napi_complete_done(napi, work_done)) { @@ -5592,6 +5597,10 @@ static int stmmac_napi_poll_tx(struct napi_struct *napi, int budget) spin_unlock_irqrestore(&ch->lock, flags); } + /* TX still have packet to handle, check if we need to arm tx timer */ + if (pending_packets) + stmmac_tx_timer_arm(priv, chan); + return work_done; } @@ -5600,6 +5609,7 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget) struct stmmac_channel *ch = container_of(napi, struct stmmac_channel, rxtx_napi); struct stmmac_priv *priv = ch->priv_data; + bool tx_pending_packets = false; int rx_done, tx_done, rxtx_done; struct stmmac_rxq_stats *rxq_stats; struct stmmac_txq_stats *txq_stats; @@ -5616,7 +5626,7 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget) txq_stats->napi_poll++; u64_stats_update_end_irqrestore(&txq_stats->syncp, flags); - tx_done = stmmac_tx_clean(priv, budget, chan); + tx_done = stmmac_tx_clean(priv, budget, chan, &tx_pending_packets); tx_done = min(tx_done, budget); rx_done = stmmac_rx_zc(priv, budget, chan); @@ -5641,6 +5651,10 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget) spin_unlock_irqrestore(&ch->lock, flags); } + /* TX still have packet to handle, check if we need to arm tx timer */ + if (tx_pending_packets) + stmmac_tx_timer_arm(priv, chan); + return min(rxtx_done, budget - 1); } From patchwork Wed Oct 18 12:35:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Marangi X-Patchwork-Id: 735509 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED490CDB482 for ; Wed, 18 Oct 2023 12:36:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344673AbjJRMgL (ORCPT ); Wed, 18 Oct 2023 08:36:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344665AbjJRMgG (ORCPT ); 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[93.34.89.13]) by smtp.googlemail.com with ESMTPSA id q28-20020adfab1c000000b003248a490e3asm2048211wrc.39.2023.10.18.05.36.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Oct 2023 05:36:01 -0700 (PDT) From: Christian Marangi To: Raju Rangoju , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Ping-Ke Shih , Kalle Valo , Simon Horman , Daniel Borkmann , Jiri Pirko , Hangbin Liu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-wireless@vger.kernel.org Cc: Christian Marangi Subject: [net-next PATCH v4 4/4] net: stmmac: increase TX coalesce timer to 5ms Date: Wed, 18 Oct 2023 14:35:50 +0200 Message-Id: <20231018123550.27110-5-ansuelsmth@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231018123550.27110-1-ansuelsmth@gmail.com> References: <20231018123550.27110-1-ansuelsmth@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Commit 8fce33317023 ("net: stmmac: Rework coalesce timer and fix multi-queue races") decreased the TX coalesce timer from 40ms to 1ms. This caused some performance regression on some target (regression was reported at least on ipq806x) in the order of 600mbps dropping from gigabit handling to only 200mbps. The problem was identified in the TX timer getting armed too much time. While this was fixed and improved in another commit, performance can be improved even further by increasing the timer delay a bit moving from 1ms to 5ms. The value is a good balance between battery saving by prevending too much interrupt to be generated and permitting good performance for internet oriented devices. Signed-off-by: Christian Marangi --- drivers/net/ethernet/stmicro/stmmac/common.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h index 1e996c29043d..e3f650e88f82 100644 --- a/drivers/net/ethernet/stmicro/stmmac/common.h +++ b/drivers/net/ethernet/stmicro/stmmac/common.h @@ -293,7 +293,7 @@ struct stmmac_safety_stats { #define MIN_DMA_RIWT 0x10 #define DEF_DMA_RIWT 0xa0 /* Tx coalesce parameters */ -#define STMMAC_COAL_TX_TIMER 1000 +#define STMMAC_COAL_TX_TIMER 5000 #define STMMAC_MAX_COAL_TX_TICK 100000 #define STMMAC_TX_MAX_FRAMES 256 #define STMMAC_TX_FRAMES 25