From patchwork Tue Nov 23 16:39:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 12634765 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8EC5C4332F for ; Tue, 23 Nov 2021 16:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238547AbhKWQpy (ORCPT ); Tue, 23 Nov 2021 11:45:54 -0500 Received: from mga14.intel.com ([192.55.52.115]:62320 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238945AbhKWQpV (ORCPT ); Tue, 23 Nov 2021 11:45:21 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10177"; a="235294780" X-IronPort-AV: E=Sophos;i="5.87,258,1631602800"; d="scan'208";a="235294780" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Nov 2021 08:42:13 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,258,1631602800"; d="scan'208";a="740631519" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by fmsmga006.fm.intel.com with ESMTP; 23 Nov 2021 08:42:03 -0800 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 1ANGf4X1016784; Tue, 23 Nov 2021 16:42:00 GMT From: Alexander Lobakin To: "David S. Miller" , Jakub Kicinski Cc: Alexander Lobakin , Jesse Brandeburg , Michal Swiatkowski , Maciej Fijalkowski , Jonathan Corbet , Shay Agroskin , Arthur Kiyanovski , David Arinzon , Noam Dagan , Saeed Bishara , Ioana Ciornei , Claudiu Manoil , Tony Nguyen , Thomas Petazzoni , Marcin Wojtas , Russell King , Saeed Mahameed , Leon Romanovsky , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?q?=C3=B8rgensen?= , John Fastabend , Edward Cree , Martin Habets , "Michael S. Tsirkin" , Jason Wang , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , KP Singh , Lorenzo Bianconi , Yajun Deng , Sergey Ryazanov , David Ahern , Andrei Vagin , Johannes Berg , Vladimir Oltean , Cong Wang , netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, bpf@vger.kernel.org, virtualization@lists.linux-foundation.org Subject: [PATCH v2 net-next 23/26] igc: bail out early on XSK xmit if no descs are available Date: Tue, 23 Nov 2021 17:39:52 +0100 Message-Id: <20211123163955.154512-24-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211123163955.154512-1-alexandr.lobakin@intel.com> References: <20211123163955.154512-1-alexandr.lobakin@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org There's no need to fetch an XSK pool desc in case our ring is full, we can rather quit under unlikely branch. Can't skip taking a lock here unfortunately since igc_desc_unused() assumes we call it being locked. This was designed to track xsk_tx::full counter, but won't hurt either way. Signed-off-by: Alexander Lobakin Reviewed-by: Jesse Brandeburg Reviewed-by: Michal Swiatkowski --- drivers/net/ethernet/intel/igc/igc_main.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.33.1 diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 8e448288ee26..7d0c540d6b76 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2604,6 +2604,8 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) __netif_tx_lock(nq, cpu); budget = igc_desc_unused(ring); + if (unlikely(!budget)) + goto out_unlock; while (xsk_tx_peek_desc(pool, &xdp_desc) && budget--) { u32 cmd_type, olinfo_status; @@ -2644,6 +2646,7 @@ static void igc_xdp_xmit_zc(struct igc_ring *ring) xsk_tx_release(pool); } +out_unlock: __netif_tx_unlock(nq); }