From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 9B33B41E9F for ; Wed, 15 Mar 2023 15:37:25 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 93BD44161A; Wed, 15 Mar 2023 15:37:25 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id BC52440A7A for ; Wed, 15 Mar 2023 15:37:23 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678891043; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=P7Ca9qIc+ex3uP+5065T1HZc3uOc+hAzgYiWpjJwJAI=; b=Q9N/UwTOuNZtehrY5IcBN3t6xOJpN63nPHb/8DwWxkNtSz4rlohwe+p33n9tQIzwBPzGdy Rv/J9jGXWMVdUYyPzgnkffvVe/i7OvHlU+j3OYSCS5tFmn4VylnFbvIETGtGPpPNso3R53 8SKGfeECWWb5jKret45kRID54iU/qFc= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-244-5leDbmqaMxOsmfWs_a59-A-1; Wed, 15 Mar 2023 10:37:22 -0400 X-MC-Unique: 5leDbmqaMxOsmfWs_a59-A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D2C7E101A554; Wed, 15 Mar 2023 14:37:21 +0000 (UTC) Received: from rh.Home (unknown [10.39.192.83]) by smtp.corp.redhat.com (Postfix) with ESMTP id 30A4240C6E67; Wed, 15 Mar 2023 14:37:21 +0000 (UTC) From: Kevin Traynor To: Yangchao Zhou Cc: Ferruh Yigit , dpdk stable Subject: patch 'kni: fix possible starvation when mbufs are exhausted' has been queued to stable release 21.11.4 Date: Wed, 15 Mar 2023 14:36:28 +0000 Message-Id: <20230315143640.677317-35-ktraynor@redhat.com> In-Reply-To: <20230315143640.677317-1-ktraynor@redhat.com> References: <20230315143640.677317-1-ktraynor@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Hi, FYI, your patch has been queued to stable release 21.11.4 Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet. It will be pushed if I get no objections before 03/20/23. So please shout if anyone has objections. Also note that after the patch there's a diff of the upstream commit vs the patch applied to the branch. This will indicate if there was any rebasing needed to apply to the stable branch. If there were code changes for rebasing (ie: not only metadata diffs), please double check that the rebase was correctly done. Queued patches are on a temporary branch at: https://github.com/kevintraynor/dpdk-stable This queued commit can be viewed at: https://github.com/kevintraynor/dpdk-stable/commit/c98bda47688aa6108067ffe917e145307b59700a Thanks. Kevin --- >From c98bda47688aa6108067ffe917e145307b59700a Mon Sep 17 00:00:00 2001 From: Yangchao Zhou Date: Fri, 30 Dec 2022 12:23:38 +0800 Subject: [PATCH] kni: fix possible starvation when mbufs are exhausted [ upstream commit 676ed80ad98fcff39943d09b8fe21e2e01ae3d4a ] In some scenarios, mbufs returned by rte_kni_rx_burst are not freed immediately. So kni_allocate_mbufs may be failed, but we don't know. Even worse, when alloc_q is completely exhausted, kni_net_tx in rte_kni.ko will drop all tx packets. kni_allocate_mbufs is never called again, even if the mbufs are eventually freed. In this patch, we try to allocate mbufs for alloc_q when it is empty. According to historical experience, the performance bottleneck of KNI is offen the usleep_range of kni thread in rte_kni.ko. The check of kni_fifo_count is trivial and the cost should be acceptable. Fixes: 3e12a98fe397 ("kni: optimize Rx burst") Signed-off-by: Yangchao Zhou Acked-by: Ferruh Yigit --- lib/kni/rte_kni.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/kni/rte_kni.c b/lib/kni/rte_kni.c index fc8f0e7b5a..149894c152 100644 --- a/lib/kni/rte_kni.c +++ b/lib/kni/rte_kni.c @@ -636,6 +636,6 @@ rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned int num) unsigned int ret = kni_fifo_get(kni->tx_q, (void **)mbufs, num); - /* If buffers removed, allocate mbufs and then put them into alloc_q */ - if (ret) + /* If buffers removed or alloc_q is empty, allocate mbufs and then put them into alloc_q */ + if (ret || (kni_fifo_count(kni->alloc_q) == 0)) kni_allocate_mbufs(kni); -- 2.39.2 --- Diff of the applied patch vs upstream commit (please double-check if non-empty: --- --- - 2023-03-15 14:30:21.445483054 +0000 +++ 0035-kni-fix-possible-starvation-when-mbufs-are-exhausted.patch 2023-03-15 14:30:20.605123769 +0000 @@ -1 +1 @@ -From 676ed80ad98fcff39943d09b8fe21e2e01ae3d4a Mon Sep 17 00:00:00 2001 +From c98bda47688aa6108067ffe917e145307b59700a Mon Sep 17 00:00:00 2001 @@ -5,0 +6,2 @@ +[ upstream commit 676ed80ad98fcff39943d09b8fe21e2e01ae3d4a ] + @@ -20 +21,0 @@ -Cc: stable@dpdk.org @@ -29 +30 @@ -index 8ab6c47153..bfa6a001ff 100644 +index fc8f0e7b5a..149894c152 100644 @@ -32 +33 @@ -@@ -635,6 +635,6 @@ rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned int num) +@@ -636,6 +636,6 @@ rte_kni_rx_burst(struct rte_kni *kni, struct rte_mbuf **mbufs, unsigned int num)