From patchwork Tue Dec 10 10:16:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 299380 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 2F4AD2C00BD for ; Tue, 10 Dec 2013 21:16:53 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753323Ab3LJKQt (ORCPT ); Tue, 10 Dec 2013 05:16:49 -0500 Received: from smtp02.citrix.com ([66.165.176.63]:53022 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753035Ab3LJKQp (ORCPT ); Tue, 10 Dec 2013 05:16:45 -0500 X-IronPort-AV: E=Sophos;i="4.93,864,1378857600"; d="scan'208";a="80373038" Received: from accessns.citrite.net (HELO FTLPEX01CL03.citrite.net) ([10.9.154.239]) by FTLPIPO02.CITRIX.COM with ESMTP; 10 Dec 2013 10:16:44 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.80) with Microsoft SMTP Server id 14.2.342.4; Tue, 10 Dec 2013 05:16:43 -0500 Received: from etemp.uk.xensource.com ([10.80.228.66] helo=etemp.uk.xensource.com.) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1VqKMu-0000pI-09; Tue, 10 Dec 2013 10:16:44 +0000 From: Paul Durrant To: , CC: Paul Durrant , Wei Liu , Ian Campbell , David Vrabel Subject: [PATCH net] xen-netback: fix abuse of napi budget Date: Tue, 10 Dec 2013 10:16:40 +0000 Message-ID: <1386670600-5882-1-git-send-email-paul.durrant@citrix.com> X-Mailer: git-send-email 1.7.10.4 MIME-Version: 1.0 X-DLP: MIA2 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org netback seemed to be somewhat confused about the napi budget parameter and basically ignored it. This patch fixes that, properly limiting the work done in each poll. Signed-off-by: Paul Durrant Cc: Wei Liu Cc: Ian Campbell Cc: David Vrabel --- drivers/net/xen-netback/netback.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 43341b8..83b4e5b 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1351,14 +1351,15 @@ static bool tx_credit_exceeded(struct xenvif *vif, unsigned size) return false; } -static unsigned xenvif_tx_build_gops(struct xenvif *vif) +static unsigned xenvif_tx_build_gops(struct xenvif *vif, int budget) { struct gnttab_copy *gop = vif->tx_copy_ops, *request_gop; struct sk_buff *skb; int ret; while ((nr_pending_reqs(vif) + XEN_NETBK_LEGACY_SLOTS_MAX - < MAX_PENDING_REQS)) { + < MAX_PENDING_REQS) && + (skb_queue_len(&vif->tx_queue) < budget)) { struct xen_netif_tx_request txreq; struct xen_netif_tx_request txfrags[XEN_NETBK_LEGACY_SLOTS_MAX]; struct page *page; @@ -1520,14 +1521,13 @@ static unsigned xenvif_tx_build_gops(struct xenvif *vif) } -static int xenvif_tx_submit(struct xenvif *vif, int budget) +static int xenvif_tx_submit(struct xenvif *vif) { struct gnttab_copy *gop = vif->tx_copy_ops; struct sk_buff *skb; int work_done = 0; - while (work_done < budget && - (skb = __skb_dequeue(&vif->tx_queue)) != NULL) { + while ((skb = __skb_dequeue(&vif->tx_queue)) != NULL) { struct xen_netif_tx_request *txp; u16 pending_idx; unsigned data_len; @@ -1602,14 +1602,14 @@ int xenvif_tx_action(struct xenvif *vif, int budget) if (unlikely(!tx_work_todo(vif))) return 0; - nr_gops = xenvif_tx_build_gops(vif); + nr_gops = xenvif_tx_build_gops(vif, budget); if (nr_gops == 0) return 0; gnttab_batch_copy(vif->tx_copy_ops, nr_gops); - work_done = xenvif_tx_submit(vif, nr_gops); + work_done = xenvif_tx_submit(vif); return work_done; }