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,USER_AGENT_GIT autolearn=unavailable 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 8E3C8C2D0EE for ; Tue, 31 Mar 2020 09:02:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F37820B80 for ; Tue, 31 Mar 2020 09:02:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645377; bh=SWSUENhegR9oYvDbEkc+SvxkJkJG6McTNOPrAMSbUFE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ACxaaKVNB5vTBl4eOhjvGOHGr08OLXUmLi2IMb1OqmxUiApa5ueE+0W0r2tEfVRYv gnbJ1g3p8iIuBbaKJPkiqy57pKEmWBUMP68VEogFThrhdAS7EohL3O67X5CgcG4FKu CnxGGeN6QLd903xkhYz6WXi8qo1Tzo049I/mxYi0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730754AbgCaJCw (ORCPT ); Tue, 31 Mar 2020 05:02:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:42472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726299AbgCaJCw (ORCPT ); Tue, 31 Mar 2020 05:02:52 -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 05945208E0; Tue, 31 Mar 2020 09:02:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585645371; bh=SWSUENhegR9oYvDbEkc+SvxkJkJG6McTNOPrAMSbUFE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GoFKZzN0R9acJcf3ZsJ4czErMdR37XaZsUIxV2jPoJJmbt5gUv7tCODEHVR8THWGJ af2iNl74tv/BINaomkah9j2sySncFvknHav/j6jkxKvnfpcAjFEKX5arO57K0StZDm q9AGoKUMmoQCk7s+15lkMOxtarrx+EUo72IHoc7A= 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 5.5 009/170] cxgb4: fix Txq restart check during backpressure Date: Tue, 31 Mar 2020 10:57:03 +0200 Message-Id: <20200331085425.145828625@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085423.990189598@linuxfoundation.org> References: <20200331085423.990189598@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 @@ -1307,8 +1307,9 @@ static inline void *write_tso_wr(struct 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; @@ -1316,12 +1317,17 @@ 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++; }