From patchwork Wed Feb 4 21:11:43 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 5779661 Return-Path: X-Original-To: patchwork-linux-wireless@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id B4386BF440 for ; Wed, 4 Feb 2015 21:11:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BC84020259 for ; Wed, 4 Feb 2015 21:11:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6E852026F for ; Wed, 4 Feb 2015 21:11:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755038AbbBDVLr (ORCPT ); Wed, 4 Feb 2015 16:11:47 -0500 Received: from mail-ig0-f176.google.com ([209.85.213.176]:38202 "EHLO mail-ig0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751023AbbBDVLp (ORCPT ); Wed, 4 Feb 2015 16:11:45 -0500 Received: by mail-ig0-f176.google.com with SMTP id hl2so37825334igb.3; Wed, 04 Feb 2015 13:11:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:subject:from:to:cc:date:in-reply-to:references :content-type:mime-version:content-transfer-encoding; bh=hIcSQnTfugdxD4U9wwd6DlhDkZj50yozbNrqiuidYMs=; b=yl1DDRRyQSeus2AqBxTF/yMRvq/Hp6UwMMAJVkJBcbzlhFlu0Th3ii2en9p5d+pVCc K0jFLYEgTyO6d5OIdcSNxIIbMUMegO5jHmqlH2umyzjgxNkIsQ0wLYXh489Vn1mrgvjU C4rw8p4XzbQ1rLf/g3QJwFdkVfhRYkAnWKm27GyR7IMHSRe6Qy1+zanHYo7JEdnfg74U E/4ByK7Nct+4bDdpjBLyJi4t3GyeC714ccDRGMzSX1fwpLBX/5xexMAwkt13oZU5KoTY /mpxmYCgPeSSuQUeQkD5PnMG6N4CLhp33L0Bs6HBCyXk+KIAG1c+WrpSRCF7F04miGRv Y9Tw== X-Received: by 10.50.39.65 with SMTP id n1mr26624880igk.37.1423084304808; Wed, 04 Feb 2015 13:11:44 -0800 (PST) Received: from ?IPv6:2620:0:1000:3e02:d973:2bfe:91c7:b4fe? ([2620:0:1000:3e02:d973:2bfe:91c7:b4fe]) by mx.google.com with ESMTPSA id b1sm10129501igl.7.2015.02.04.13.11.43 (version=TLSv1.2 cipher=AES128-GCM-SHA256 bits=128/128); Wed, 04 Feb 2015 13:11:44 -0800 (PST) Message-ID: <1423084303.31870.15.camel@edumazet-glaptop2.roam.corp.google.com> Subject: Re: Throughput regression with `tcp: refine TSO autosizing` From: Eric Dumazet To: Michal Kazior Cc: Neal Cardwell , linux-wireless , Network Development , eyalpe@dev.mellanox.co.il Date: Wed, 04 Feb 2015 13:11:43 -0800 In-Reply-To: <1423056591.907.130.camel@edumazet-glaptop2.roam.corp.google.com> References: <1422537297.21689.15.camel@edumazet-glaptop2.roam.corp.google.com> <1422628835.21689.95.camel@edumazet-glaptop2.roam.corp.google.com> <1422903136.21689.114.camel@edumazet-glaptop2.roam.corp.google.com> <1422926330.21689.138.camel@edumazet-glaptop2.roam.corp.google.com> <1422973660.907.10.camel@edumazet-glaptop2.roam.corp.google.com> <1423051045.907.108.camel@edumazet-glaptop2.roam.corp.google.com> <1423053531.907.115.camel@edumazet-glaptop2.roam.corp.google.com> <1423055810.907.125.camel@edumazet-glaptop2.roam.corp.google.com> <1423056591.907.130.camel@edumazet-glaptop2.roam.corp.google.com> X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP I do not see how a TSO patch could hurt a flow not using TSO/GSO. This makes no sense. ath10k tx completions being batched/deferred to a tasklet might increase probability to hit this condition in tcp_wfree() : /* If this softirq is serviced by ksoftirqd, we are likely under stress. * Wait until our queues (qdisc + devices) are drained. * This gives : * - less callbacks to tcp_write_xmit(), reducing stress (batches) * - chance for incoming ACK (processed by another cpu maybe) * to migrate this flow (skb->ooo_okay will be eventually set) */ if (wmem >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current) goto out; Meaning tcp stack waits all skbs left qdisc/NIC queues before queuing additional packets. I would try to call skb_orphan() in ath10k if you really want to keep these batches. I have hard time to understand why tx completed packets go through ath10k_htc_rx_completion_handler().. anyway... Most conservative patch would be : --- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c index 9c782a42665e1aaf43bfbca441631ee58da50c09..6a36317d6bb0447202dee15528130bd5e21248c4 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -1642,6 +1642,7 @@ void ath10k_htt_t2h_msg_handler(struct ath10k *ar, struct sk_buff *skb) break; } case HTT_T2H_MSG_TYPE_TX_COMPL_IND: + skb_orphan(skb); spin_lock_bh(&htt->tx_lock); __skb_queue_tail(&htt->tx_compl_q, skb); spin_unlock_bh(&htt->tx_lock);