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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 3D8AFC2D0E8 for ; Tue, 31 Mar 2020 09:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14E0520787 for ; Tue, 31 Mar 2020 09:11:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645890; bh=O3FDISHoAiPz15RmgglneoLtgMFI0IG2j0nxtYl0R+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=TO2GOiZlTsLKL2BMyGJzNKtaclS+T7fn8qgQvKgVOMtcHkAsnwn/lVU7KK2iSgfvp dLBf90GvD7PTyRJVfAizCtbvBAii1EiKklzb4H+BOQmKQQSIWmkqes3fC4gywUm7NX h/sU5xhrBtds+7g/ZVVb7UNO6H1o6hdzZh1Hy8Qo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731702AbgCaJL1 (ORCPT ); Tue, 31 Mar 2020 05:11:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:56340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731430AbgCaJL0 (ORCPT ); Tue, 31 Mar 2020 05:11:26 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B8F7620675; Tue, 31 Mar 2020 09:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645886; bh=O3FDISHoAiPz15RmgglneoLtgMFI0IG2j0nxtYl0R+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ISNcEtL66sClbH2l5CBysWqkqswo7Wps2MGoE5ortdnEQvqwINzv8WNH/1cK3mcAD z/WGS2ILoTWb54tUeyv8/t02wM6sQ9IEW9Z83rHi/bDHvsUekiW2MrwSBALjcY137p Y1RvrUEvSdxs0d/YowZBxz/5DkD2KKRzvbjm9N2Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rahul Lakkireddy , "David S. Miller" Subject: [PATCH 5.4 008/155] cxgb4: fix Txq restart check during backpressure Date: Tue, 31 Mar 2020 10:57:28 +0200 Message-Id: <20200331085419.325664975@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085418.274292403@linuxfoundation.org> References: <20200331085418.274292403@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rahul Lakkireddy [ Upstream commit f1f20a8666c55cb534b8f3fc1130eebf01a06155 ] Driver reclaims descriptors in much smaller batches, even if hardware indicates more to reclaim, during backpressure. So, fix the check to restart the Txq during backpressure, by looking at how many descriptors hardware had indicated to reclaim, and not on how many descriptors that driver had actually reclaimed. Once the Txq is restarted, driver will reclaim even more descriptors when Tx path is entered again. Fixes: d429005fdf2c ("cxgb4/cxgb4vf: Add support for SGE doorbell queue timer") Signed-off-by: Rahul Lakkireddy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/chelsio/cxgb4/sge.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/chelsio/cxgb4/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c @@ -1324,8 +1324,9 @@ static inline void t6_fill_tnl_lso(struc int t4_sge_eth_txq_egress_update(struct adapter *adap, struct sge_eth_txq *eq, int maxreclaim) { + unsigned int reclaimed, hw_cidx; struct sge_txq *q = &eq->q; - unsigned int reclaimed; + int hw_in_use; if (!q->in_use || !__netif_tx_trylock(eq->txq)) return 0; @@ -1333,12 +1334,17 @@ int t4_sge_eth_txq_egress_update(struct /* Reclaim pending completed TX Descriptors. */ reclaimed = reclaim_completed_tx(adap, &eq->q, maxreclaim, true); + hw_cidx = ntohs(READ_ONCE(q->stat->cidx)); + hw_in_use = q->pidx - hw_cidx; + if (hw_in_use < 0) + hw_in_use += q->size; + /* If the TX Queue is currently stopped and there's now more than half * the queue available, restart it. Otherwise bail out since the rest * of what we want do here is with the possibility of shipping any * currently buffered Coalesced TX Work Request. */ - if (netif_tx_queue_stopped(eq->txq) && txq_avail(q) > (q->size / 2)) { + if (netif_tx_queue_stopped(eq->txq) && hw_in_use < (q->size / 2)) { netif_tx_wake_queue(eq->txq); eq->q.restarts++; }