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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 89617C433E2 for ; Fri, 4 Sep 2020 14:28:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 564EA206B7 for ; Fri, 4 Sep 2020 14:28:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YP4MEoPB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730567AbgIDO2V (ORCPT ); Fri, 4 Sep 2020 10:28:21 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:54806 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730443AbgIDO2F (ORCPT ); Fri, 4 Sep 2020 10:28:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599229684; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IwmZ+bkJtm1ptxZ/ECWY3T+CE7HjdpigE1Uh+r6cTW0=; b=YP4MEoPBFQKaIOtge/4YcHgdykmnj9kE4kK/odI8VpzhKMvSGvH0uiGpJGSD8a7+O4E8cz 7pxRCMJQhOGdtVwUJE7OBUir5jFkLFL1pflo54wLu/L7JJIzRwQOUwA1HfSQeluLK3+Hmf YRaz5MNmKje4iPd4QsIPun0r58bZTz4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-40-O8hj-laNPdC0L1rxOxwNlw-1; Fri, 04 Sep 2020 10:28:02 -0400 X-MC-Unique: O8hj-laNPdC0L1rxOxwNlw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 21AC1A0BC3; Fri, 4 Sep 2020 14:28:00 +0000 (UTC) Received: from carbon (unknown [10.40.208.42]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0C23B5D9CC; Fri, 4 Sep 2020 14:27:53 +0000 (UTC) Date: Fri, 4 Sep 2020 16:27:51 +0200 From: Jesper Dangaard Brouer To: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Eric Dumazet Cc: brouer@redhat.com, ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org, bpf@vger.kernel.org, magnus.karlsson@intel.com, bjorn.topel@intel.com, davem@davemloft.net, kuba@kernel.org, john.fastabend@gmail.com, intel-wired-lan@lists.osuosl.org Subject: Re: [PATCH bpf-next 0/6] xsk: exit NAPI loop when AF_XDP Rx ring is full Message-ID: <20200904162751.632c4443@carbon> In-Reply-To: <20200904135332.60259-1-bjorn.topel@gmail.com> References: <20200904135332.60259-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, 4 Sep 2020 15:53:25 +0200 Bj=C3=B6rn T=C3=B6pel wrote: > On my machine the "one core scenario Rx drop" performance went from > ~65Kpps to 21Mpps. In other words, from "not usable" to > "usable". YMMV. We have observed this kind of dropping off an edge before with softirq (when userspace process runs on same RX-CPU), but I thought that Eric Dumazet solved it in 4cd13c21b207 ("softirq: Let ksoftirqd do its job"). I wonder what makes AF_XDP different or if the problem have come back? --=20 Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer