From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27380C282E3 for ; Thu, 25 Apr 2019 08:38:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC1BA208E4 for ; Thu, 25 Apr 2019 08:38:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="BaFnAWbJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729898AbfDYIiu (ORCPT ); Thu, 25 Apr 2019 04:38:50 -0400 Received: from nbd.name ([46.4.11.11]:59698 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729858AbfDYIir (ORCPT ); Thu, 25 Apr 2019 04:38:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=References:In-Reply-To:Message-Id:Date:Subject:To:From:Sender: Reply-To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=3lUfNj/2xwklNxFMVrG1nfHEGpykdhYCaDMUOMmbC/g=; b=BaFnAWbJlUCi546JDGzDlu+oNR wBaI20HtrSGZfRzUTzJlME/C+KdPbtlC2gZ9zpQPAqMUcpyBjrR/+yD+taxFXOLNymKOYTCfzW5m3 eNgUO+RVcgXlvF8gVlsXr2/lWQV8ZCkKVlxq15D/hhO1TqUZM0CEDZi5vl/0ragQEhK8=; Received: from p54ae9e78.dip0.t-ipconnect.de ([84.174.158.120] helo=maeck-2.local) by ds12 with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hJZu1-0002Bn-MJ for linux-wireless@vger.kernel.org; Thu, 25 Apr 2019 10:38:45 +0200 Received: by maeck-2.local (Postfix, from userid 501) id 0D01659A3377; Thu, 25 Apr 2019 10:38:44 +0200 (CEST) From: Felix Fietkau To: linux-wireless@vger.kernel.org Subject: [PATCH v2 2/5] mt76: reduce locking in mt76_dma_tx_cleanup Date: Thu, 25 Apr 2019 10:38:41 +0200 Message-Id: <20190425083844.14186-2-nbd@nbd.name> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20190425083844.14186-1-nbd@nbd.name> References: <20190425083844.14186-1-nbd@nbd.name> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org q->tail can be safely updated without locking, because there is no concurrent access. If called from outside of the tasklet (for flushing), the tasklet is always disabled. q->queued can be safely read without locking, as long as the decrement happens within the locked section. This patch allows cleaning up tx packets outside of the section that holds the queue lock for improved performance Signed-off-by: Felix Fietkau --- drivers/net/wireless/mediatek/mt76/dma.c | 26 ++++++++++++++++-------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c index 7145b75b6438..e4a5b34915bf 100644 --- a/drivers/net/wireless/mediatek/mt76/dma.c +++ b/drivers/net/wireless/mediatek/mt76/dma.c @@ -149,31 +149,29 @@ mt76_dma_tx_cleanup(struct mt76_dev *dev, enum mt76_txq_id qid, bool flush) struct mt76_sw_queue *sq = &dev->q_tx[qid]; struct mt76_queue *q = sq->q; struct mt76_queue_entry entry; + unsigned int n_swq_queued[4] = {}; + unsigned int n_queued = 0; bool wake = false; - int last; + int i, last; if (!q) return; - spin_lock_bh(&q->lock); if (flush) last = -1; else last = readl(&q->regs->dma_idx); - while (q->queued && q->tail != last) { + while ((q->queued > n_queued) && q->tail != last) { mt76_dma_tx_cleanup_idx(dev, q, q->tail, &entry); if (entry.schedule) - dev->q_tx[entry.qid].swq_queued--; + n_swq_queued[entry.qid]++; q->tail = (q->tail + 1) % q->ndesc; - q->queued--; + n_queued++; - if (entry.skb) { - spin_unlock_bh(&q->lock); + if (entry.skb) dev->drv->tx_complete_skb(dev, qid, &entry); - spin_lock_bh(&q->lock); - } if (entry.txwi) { mt76_put_txwi(dev, entry.txwi); @@ -184,6 +182,16 @@ mt76_dma_tx_cleanup(struct mt76_dev *dev, enum mt76_txq_id qid, bool flush) last = readl(&q->regs->dma_idx); } + spin_lock_bh(&q->lock); + + q->queued -= n_queued; + for (i = 0; i < ARRAY_SIZE(n_swq_queued); i++) { + if (!n_swq_queued[i]) + continue; + + dev->q_tx[i].swq_queued -= n_swq_queued[i]; + } + if (flush) mt76_dma_sync_idx(dev, q); -- 2.17.0