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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B93CDCA9EA0 for ; Sun, 20 Oct 2019 17:07:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 852A321897 for ; Sun, 20 Oct 2019 17:07:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uiGX7Fa6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726556AbfJTRHd (ORCPT ); Sun, 20 Oct 2019 13:07:33 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:38968 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbfJTRHd (ORCPT ); Sun, 20 Oct 2019 13:07:33 -0400 Received: by mail-pg1-f193.google.com with SMTP id p12so6183053pgn.6; Sun, 20 Oct 2019 10:07:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XctxpsmH04LYAq9WgHg+9E0PoY+xS1FvDl3lkgy7Py8=; b=uiGX7Fa6jkw9jaMvT1N9aYHq6RJ87nVEY2tRGdC10we5yLZh1nhR+IYEcUgx+fRX2Y vujMyCZ2ST/xKI2BJt7ZHauoVPh7jBNn9f/fPhPOkciHuGuMveadyFaRxMIC0R/p0CMH cK+ZlL3N92jOX/nvaUNz5OWW0EFIHB6aSG0I0+hI+5kFxO2qoqRUhLWPHFXv8D2nSJny 9CX/wQQryqXTcY1X78UTkNDKHJ4g8Wa/D3XHOpAHaJRsR+YimsOneXmcxnNOcE9PNPXz rdxufxhSLH6qVYVf+jkcMhKo37yPEjWvoecRC1PGbgPyDCKosRo5pIpkkRh9vAlcHmLJ dUyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XctxpsmH04LYAq9WgHg+9E0PoY+xS1FvDl3lkgy7Py8=; b=pRyjpgM+KYGI2gwFNiUYlZ9+jR9iHmCrkK7tVu/XiWBHOXc08UILDPpKxgZPZshUNQ cHuXQ3WT2M0jXrRKoIBKFF6H+R+XKw9SIWb2qz0y+eytn3DlK7QJMPj3h5YB6ZGV9XrI gVWcVd7cgFGLcxww2+NY74aEQCbWn8Iy1RjRuNKraYZNY6SUR2lDUz6kRada+cpA/I7j gNgCOLpIhbl1zXn6K9ke5Bm3dZ1mq7FvjZLg/BlpcsBmgQuPwzdcjBx562br10Nw3Po0 aRdlGkrBXnQUJxK/p0TkDvQdEifT/5iIEbYMUK8c7dzm25rNhelD7VVPWotTQwISohgg 215A== X-Gm-Message-State: APjAAAW1siyiP5BBDVRqEeFTGQJBCuXrZm7fFvuXaH8tKaiDysN53O0o +n17vpqHg2FW7Dv8d1UAyWRhRlWYBzs= X-Google-Smtp-Source: APXvYqy+oa+Wg/7TkIRpXSWGt26Om7+b1X9j+71p8xQGTZMa+OUseW1xu6jQ1IWlC6WxCQzpWIbS8A== X-Received: by 2002:a62:4ed6:: with SMTP id c205mr17623065pfb.170.1571591251752; Sun, 20 Oct 2019 10:07:31 -0700 (PDT) Received: from btopel-mobl.ger.intel.com ([192.55.54.42]) by smtp.gmail.com with ESMTPSA id y8sm15938996pgs.34.2019.10.20.10.07.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 20 Oct 2019 10:07:30 -0700 (PDT) From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , bpf@vger.kernel.org, magnus.karlsson@gmail.com, magnus.karlsson@intel.com, toke@redhat.com, sridhar.samudrala@intel.com Subject: [PATCH bpf-next] libbpf: remove explicit XSKMAP lookup from AF_XDP XDP program Date: Sun, 20 Oct 2019 19:07:11 +0200 Message-Id: <20191020170711.22082-1-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Björn Töpel In commit 43e74c0267a3 ("bpf_xdp_redirect_map: Perform map lookup in eBPF helper") the bpf_redirect_map() helper learned to do map lookup, which means that the explicit lookup in the XDP program for AF_XDP is not needed. This commit removes the map lookup, which simplifies the BPF code and improves the performance for the "rx_drop" [1] scenario with ~4%. [1] # xdpsock -i eth0 -z -r Suggested-by: Toke Høiland-Jørgensen Signed-off-by: Björn Töpel --- tools/lib/bpf/xsk.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index b0f532544c91..8e35de3cb443 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -278,29 +278,15 @@ static int xsk_load_xdp_prog(struct xsk_socket *xsk) * * // A set entry here means that the correspnding queue_id * // has an active AF_XDP socket bound to it. - * if (bpf_map_lookup_elem(&xsks_map, &index)) - * return bpf_redirect_map(&xsks_map, index, 0); - * - * return XDP_PASS; + * return bpf_redirect_map(&xsks_map, index, XDP_PASS); * } */ struct bpf_insn prog[] = { - /* r1 = *(u32 *)(r1 + 16) */ - BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_1, 16), - /* *(u32 *)(r10 - 4) = r1 */ - BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_1, -4), - BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), - BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), - BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd), - BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), - BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), - BPF_MOV32_IMM(BPF_REG_0, 2), - /* if r1 == 0 goto +5 */ - BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 5), - /* r2 = *(u32 *)(r10 - 4) */ + /* r2 = *(u32 *)(r1 + 16) */ + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 16), BPF_LD_MAP_FD(BPF_REG_1, xsk->xsks_map_fd), - BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_10, -4), - BPF_MOV32_IMM(BPF_REG_3, 0), + /* r3 = XDP_PASS */ + BPF_MOV32_IMM(BPF_REG_3, 2), BPF_EMIT_CALL(BPF_FUNC_redirect_map), /* The jumps are to this instruction */ BPF_EXIT_INSN(), -- 2.20.1