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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 2ECD3C433DF for ; Thu, 20 Aug 2020 08:13:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0967320855 for ; Thu, 20 Aug 2020 08:13:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597911212; bh=c8IHdpgUofJgH17OfpXZ8mbOL/0v2aSMDySpoG9Nz7I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=n9QK0HBkDIeJIzWJrj8Om45hmyS6+BnQkJpHHhi/4ciCENYdTbxymoPnpNPDS0aB2 eIMhKJPtxXb1O6JZVTUGfODr2RIqROvslIo9kPwJ3l0PjGW4TL+A06XxZx/1bxQJKo nDr9s8qkoQDT3G/llw5L1aQZrqLhMZVuDA0O8Q48= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726817AbgHTIN0 (ORCPT ); Thu, 20 Aug 2020 04:13:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:50686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726435AbgHTIL5 (ORCPT ); Thu, 20 Aug 2020 04:11:57 -0400 Received: from localhost (unknown [151.48.139.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EC1632080C; Thu, 20 Aug 2020 08:11:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597911116; bh=c8IHdpgUofJgH17OfpXZ8mbOL/0v2aSMDySpoG9Nz7I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oKwgTUmAdkALKJDRRj4Cjyg0AlWIbAJUE2V7l9vNGmse9rVdUg8vZzma7s6YVNjeT yKRbli8jtCRIKTbrnp51ppin3BhdOd5ErjgvzvXYUg9CRI3szsxci+jLNLSvu26YuB YdajDecUojy75S73O27vu6bz8mT93ejIcrmig0HA= Date: Thu, 20 Aug 2020 10:11:51 +0200 From: Lorenzo Bianconi To: Jesper Dangaard Brouer Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net, lorenzo.bianconi@redhat.com, echaudro@redhat.com, sameehj@amazon.com, kuba@kernel.org Subject: Re: [PATCH net-next 3/6] net: mvneta: update mb bit before passing the xdp buffer to eBPF layer Message-ID: <20200820081151.GD2282@lore-desk> References: <08f8656e906ff69bd30915a6a37a01d5f0422194.1597842004.git.lorenzo@kernel.org> <20200820100215.1b93464f@carbon> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="bjuZg6miEcdLYP6q" Content-Disposition: inline In-Reply-To: <20200820100215.1b93464f@carbon> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --bjuZg6miEcdLYP6q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > On Wed, 19 Aug 2020 15:13:48 +0200 > Lorenzo Bianconi wrote: >=20 > > Update multi-buffer bit (mb) in xdp_buff to notify XDP/eBPF layer and > > XDP remote drivers if this is a "non-linear" XDP buffer > >=20 > > Signed-off-by: Lorenzo Bianconi > > --- > > drivers/net/ethernet/marvell/mvneta.c | 3 +++ > > 1 file changed, 3 insertions(+) > >=20 > > diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethern= et/marvell/mvneta.c > > index 832bbb8b05c8..36a3defa63fa 100644 > > --- a/drivers/net/ethernet/marvell/mvneta.c > > +++ b/drivers/net/ethernet/marvell/mvneta.c > > @@ -2170,11 +2170,14 @@ mvneta_run_xdp(struct mvneta_port *pp, struct m= vneta_rx_queue *rxq, > > struct bpf_prog *prog, struct xdp_buff *xdp, > > u32 frame_sz, struct mvneta_stats *stats) > > { > > + struct skb_shared_info *sinfo =3D xdp_get_shared_info_from_buff(xdp); > > unsigned int len, data_len, sync; > > u32 ret, act; > > =20 > > len =3D xdp->data_end - xdp->data_hard_start - pp->rx_offset_correcti= on; > > data_len =3D xdp->data_end - xdp->data; > > + > > + xdp->mb =3D !!sinfo->nr_frags; > > act =3D bpf_prog_run_xdp(prog, xdp); >=20 > Reading the memory sinfo->nr_frags could be a performance issue for our > baseline case of no-multi-buffer. As you are reading a cache-line that > you don't need to (and driver have not touch yet). ack, I will rework it in v2 to remove this access. Regards, Lorenzo >=20 > --=20 > Best regards, > Jesper Dangaard Brouer > MSc.CS, Principal Kernel Engineer at Red Hat > LinkedIn: http://www.linkedin.com/in/brouer >=20 --bjuZg6miEcdLYP6q Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTquNwa3Txd3rGGn7Y6cBh0uS2trAUCXz4wRQAKCRA6cBh0uS2t rAZnAQD1n0h+sVSzJJUmmzYyNKV4sDY19aLV1SX6fSfEySCZRAD+PJnaOgAaSgCY yd/VrWsb7Q3N6DqR1U2cVv+tkdaoPA8= =ZqCa -----END PGP SIGNATURE----- --bjuZg6miEcdLYP6q--