From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 0D212A0093; Fri, 17 Jun 2022 11:37:33 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id F1DA340F19; Fri, 17 Jun 2022 11:37:32 +0200 (CEST) Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by mails.dpdk.org (Postfix) with ESMTP id 7468840698 for <dev@dpdk.org>; Fri, 17 Jun 2022 11:37:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655458651; x=1686994651; h=from:to:cc:subject:date:message-id; bh=ofjTWcZe62Kbz9zyYyFQn11CbAthGFiNnx1GodE0RNA=; b=V48jnDNL3OjN/O2tWDiaviqB714dARPZuXSduoHZcRp0P0gDFFiItf9u 6Bq1MMkBpcSIbQJBsZc/DjXsG2jzgp9SuTi7g7Bs5Tg7A0S420AfKHcNK KaHITN5Zz8nUfRQwlnno6HLTgFYbJN5aAYrgP7d/rQYh9VfS3RonWQkYs UJR9pWuMBAzPwgEtwCH7qwhy21icRdIIUMXklZ0zmNI/XESP6pPJpZRTC eVTeY951n3cQGlUliSUiUBuKcKDfEPcwWnA1spgPHNM50YB++YPsU3FRZ KDCewz+dXcE99o0CunaWzZHBGaABY8+nK7fOxb3+HWjtB07E2kqBfT4fN g==; X-IronPort-AV: E=McAfee;i="6400,9594,10380"; a="341120343" X-IronPort-AV: E=Sophos;i="5.92,306,1650956400"; d="scan'208";a="341120343" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jun 2022 02:37:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,306,1650956400"; d="scan'208";a="590052855" Received: from npg-dpdk-xuan-cbdma.sh.intel.com ([10.67.110.228]) by fmsmga007.fm.intel.com with ESMTP; 17 Jun 2022 02:37:28 -0700 From: xuan.ding@intel.com To: maxime.coquelin@redhat.com, chenbo.xia@intel.com Cc: dev@dpdk.org, jiayu.hu@intel.com, Xuan Ding <xuan.ding@intel.com> Subject: [PATCH] doc: update async enqueue API usage Date: Fri, 17 Jun 2022 09:34:13 +0000 Message-Id: <20220617093413.94960-1-xuan.ding@intel.com> X-Mailer: git-send-email 2.17.1 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org From: Xuan Ding <xuan.ding@intel.com> This patch updates the correct usage for async enqueue APIs. The rte_vhost_poll_enqueue_completed() needs to be called in time to avoid packet loss due to full dma ring. Signed-off-by: Xuan Ding <xuan.ding@intel.com> --- doc/guides/prog_guide/vhost_lib.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst index cd3f6caa9a..9cdd7da154 100644 --- a/doc/guides/prog_guide/vhost_lib.rst +++ b/doc/guides/prog_guide/vhost_lib.rst @@ -488,3 +488,12 @@ For PA mode, page by page mapping may exceed IOMMU's max capability, better to use 1G guest hugepage. For UIO driver, any VFIO related error message can be ignored. + +Async enqueue API usage +----------------------- + +In async enqueue path, rte_vhost_poll_enqueue_completed() needs to be +called in time. Otherwise, calling rte_vhost_submit_enqueue_burst() +all the time will cause the DMA ring to be full, which will result +in packet loss eventually. + -- 2.17.1