From patchwork Wed Apr 10 07:09:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Magnus Karlsson X-Patchwork-Id: 1083215 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44fFdh4W1Wz9s0W for ; Wed, 10 Apr 2019 17:09:28 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728840AbfDJHJ2 (ORCPT ); Wed, 10 Apr 2019 03:09:28 -0400 Received: from mga06.intel.com ([134.134.136.31]:54211 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725909AbfDJHJ1 (ORCPT ); Wed, 10 Apr 2019 03:09:27 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Apr 2019 00:09:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,332,1549958400"; d="scan'208";a="290256235" Received: from mkarlsso-mobl.ger.corp.intel.com (HELO VM.isw.intel.com) ([10.103.211.40]) by orsmga004.jf.intel.com with ESMTP; 10 Apr 2019 00:09:22 -0700 From: Magnus Karlsson To: magnus.karlsson@intel.com, bjorn.topel@intel.com, ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org Cc: bpf@vger.kernel.org, bruce.richardson@intel.com, ciara.loftus@intel.com, ilias.apalodimas@linaro.org, xiaolong.ye@intel.com, ferruh.yigit@intel.com, qi.z.zhang@intel.com, georgmueller@gmx.net Subject: [PATCH bpf v2 1/2] libbpf: remove likely/unlikely in xsk.h Date: Wed, 10 Apr 2019 09:09:13 +0200 Message-Id: <1554880154-30791-2-git-send-email-magnus.karlsson@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1554880154-30791-1-git-send-email-magnus.karlsson@intel.com> References: <1554880154-30791-1-git-send-email-magnus.karlsson@intel.com> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-Id: netdev.vger.kernel.org This patch removes the use of likely and unlikely in xsk.h since they create a dependency on Linux headers as reported by several users. There have also been reports that the use of these decreases performance as the compiler puts the code on two different cache lines instead of on a single one. All in all, I think we are better off without them. Fixes: 1cad07884239 ("libbpf: add support for using AF_XDP sockets") Signed-off-by: Magnus Karlsson --- tools/lib/bpf/xsk.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index a497f00..3638147 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -105,7 +105,7 @@ static inline __u32 xsk_cons_nb_avail(struct xsk_ring_cons *r, __u32 nb) static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod, size_t nb, __u32 *idx) { - if (unlikely(xsk_prod_nb_free(prod, nb) < nb)) + if (xsk_prod_nb_free(prod, nb) < nb) return 0; *idx = prod->cached_prod; @@ -129,7 +129,7 @@ static inline size_t xsk_ring_cons__peek(struct xsk_ring_cons *cons, { size_t entries = xsk_cons_nb_avail(cons, nb); - if (likely(entries > 0)) { + if (entries > 0) { /* Make sure we do not speculatively read the data before * we have received the packet buffers from the ring. */