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 Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by smtp.lore.kernel.org (Postfix) with ESMTP id 888CDEC1113 for ; Mon, 23 Feb 2026 17:40:11 +0000 (UTC) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 06E64402EF; Mon, 23 Feb 2026 18:40:10 +0100 (CET) Received: from mail-ot1-f42.google.com (mail-ot1-f42.google.com [209.85.210.42]) by mails.dpdk.org (Postfix) with ESMTP id 9A90D4025E for ; Mon, 23 Feb 2026 18:40:08 +0100 (CET) Received: by mail-ot1-f42.google.com with SMTP id 46e09a7af769-7d19bfe1190so3834508a34.1 for ; Mon, 23 Feb 2026 09:40:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1771868408; x=1772473208; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=95N4RbviGqf9gyepjL6CN78d8iE6aiokF3JGOasWYYU=; b=qql1yuqYjQXDR7WhJpoE2NHqwG3c1CkXOOy3FiyVco9xuIgNh38qcGPh9hRNhPuH9y C9PMIu/35xkB+/x8cEInb6SeDemSB7zDjP8E4KTl6o1hc2ClUvDy4r2fbGTblexHVR5f sMEQf9HvdylaGqckwCN6EkAxyEak97FidycDgWveV0/uqYgOL+P1D08k9hV898hoUIzQ Lzrob1CXUXVP9hvZ7LzX/B1By85X3FOZP+McAXTmsziBQradKRzYXxhTXjVyxw88LF5n Dd31SpUG04yNzCMPVHJ9KbIsE/Cf/qjCIabgr93SrzTUAcdWpBRC3LkNVQgJltMDahZN tovg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771868408; x=1772473208; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=95N4RbviGqf9gyepjL6CN78d8iE6aiokF3JGOasWYYU=; b=PymBXB3gHT5YD1CkqGCi9NBJmbWgrow9lxcdKgVbKOBz6uVEJw6d8O4wB+QISsNQ9J SrUVPfpvlezBUILPhalOvBeUh48q0kZIdkeSbVVd0kHtYn+t/ND47CrNVFyufF9Bp9KY t+8zyuB67i+t1uvz/sOEYQJg9kKYstNE1z8zgkrurnRzAPwp7kBuZDYLU1+0vIuaHLga QUdxS5sxrlM9GABi2NpBsm/y5KgwA4eIJNWwgqVpN6i3vzynHRlnTMzWAhe0WN5g0ivd Dyn5PvpVXUfYNo8jEuOXw7iyXiQpZXbYe4gj0Go4TSiNyvlpbIqellevDrRyoT7oKYap cqdw== X-Gm-Message-State: AOJu0Yz5gV2KOK/+RF+UPmjMvXKFKbkSRoahmXjfmtpgecWHeozSv5KX VjrEvJFo87MTQLdgCH+RvnkitkDaoktrc6XJ4DCQlBks8pGWShx2ZxSJzzYaa1PuJLc= X-Gm-Gg: AZuq6aKLRF26l82W/hoyqqzsHAnhhDv3DFw62DeYeKIUktLg7Gnm+rfWAn0Xr95Fn0t rmocPsSosc14R1yLWVyexDFYwjz3SgsgKxdXx6E5FzX4tfO8Wv/pCgtrZetETqzQqtFYINPTbyI FMXgpegIhs4E/VJo2tUcJeA2KjBEr+QAkb+L75GjLfG8OOLTPMhXJd6WeX2mdhPm5h3zIdlhNL+ 15VFcqsOPwEQ6eCamqM0dspFtu1sbJZBB8jBoNiE2xHronI0Hmd3HxyJg6s1FIpnA+lFfl7wGRe 3/+PsdDW7mZZnQQQ5odCUQALVHhbkUAKFkqE1qy/SE6uvjYkWSXdpYaGwHb/xPjPgbkqURkxpqW tOW4PPNvMMDWkUKG638wVMH3GUwKyNxvy4+kP/N9abvLxf6Rj8mG1OxTjEEt8Yz12gjw82Ne5DL Mlu1HmJl0x7TXtzWPYdR4Of8CXQRGk0P8FIcVOImksBfMpNmyhX+qzW97Sr8xCBTE3 X-Received: by 2002:a05:6830:90b:b0:7cc:4d72:586e with SMTP id 46e09a7af769-7d52be3bfb2mr6755503a34.9.1771868407690; Mon, 23 Feb 2026 09:40:07 -0800 (PST) Received: from phoenix.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7d52d04c637sm7591742a34.19.2026.02.23.09.40.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Feb 2026 09:40:07 -0800 (PST) Date: Mon, 23 Feb 2026 09:40:04 -0800 From: Stephen Hemminger To: longli@linux.microsoft.com Cc: dev@dpdk.org, Wei Hu , stable@dpdk.org, Dariusz Sosnowski , Viacheslav Ovsiienko , Bing Zhao , Ori Kam , Suanming Mou , Matan Azrad , Long Li Subject: Re: [PATCH v2 2/8] net/netvsc: fix race conditions on VF add/remove events Message-ID: <20260223094004.445914ee@phoenix.local> In-Reply-To: <20260221024540.659098-2-longli@linux.microsoft.com> References: <20260221024540.659098-1-longli@linux.microsoft.com> <20260221024540.659098-2-longli@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On Fri, 20 Feb 2026 18:45:21 -0800 longli@linux.microsoft.com wrote: > + rte_rwlock_read_lock(&hv->vf_lock); > + vf_dev = hn_get_vf_dev(hv); > + if (hv->vf_ctx.vf_vsc_switched && vf_dev && > + vf_dev->data->dev_started) { > + void *sub_q = vf_dev->data->tx_queues[queue_id]; > + > + nb_tx = (*vf_dev->tx_pkt_burst) > + (sub_q, tx_pkts, nb_pkts); > rte_rwlock_read_unlock(&hv->vf_lock); > + return nb_tx; > } > + rte_rwlock_read_unlock(&hv->vf_lock); ok, but read locks not free. It does incur an additional cache miss which may impact performance. Might be better in future to have some form of lockless access here.