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 350F0C54EAA for ; Mon, 30 Jan 2023 08:27:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236000AbjA3I07 (ORCPT ); Mon, 30 Jan 2023 03:26:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229741AbjA3I06 (ORCPT ); Mon, 30 Jan 2023 03:26:58 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EEF62411A for ; Mon, 30 Jan 2023 00:26:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675067171; 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=6AGVQkEQGPmbyUHabR74dVCVn0EngYdjpKD75ZNVK50=; b=JaMJkX/kFTRYFpl1n1w1BoNKqIddtX4QgzJPkFYPkD/3L0GongVYjPwKC+wySToplsE8Up 1K7Y0KWvMmwHIU8qWcp6t6yAFD0/oY4KpF63JWhVtpa0gZhmAExf6BkPDoGZrihjtyPzPL PZJWNA3OWmk5IWCyqg5DWRQ0SJUDoAY= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-294-Fbbipx2sODm9nKrtVsQkSA-1; Mon, 30 Jan 2023 03:26:09 -0500 X-MC-Unique: Fbbipx2sODm9nKrtVsQkSA-1 Received: by mail-qt1-f198.google.com with SMTP id bp43-20020a05622a1bab00b003b63be6827dso4675891qtb.23 for ; Mon, 30 Jan 2023 00:26:09 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:user-agent:content-transfer-encoding:references :in-reply-to:date:cc:to:from:subject:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=6AGVQkEQGPmbyUHabR74dVCVn0EngYdjpKD75ZNVK50=; b=PVfbo2nXks7mfRDhsxL7TJM7wLGkEEjH4gqMyqA2ANIdUViORbekxtzOV+J6VN6RO3 0vkVYRSNTk5lA7X1NEOaNQ9FrrRIdTSVarYsU4I5kUtO8Hn0A6+F3JQw0AK+V+BW7Lww fUwnmekXMUhxfjQow4gY9Xxo7AalVQMnJdN0elgix1G9B1XaLjKY4vkq1l+NZqgVaZox H6TITTplG8dK1NZuWXueAZfqUU9w+frE4AXr4Iao5BAVbOFwwWox74G7aWozOVOCMbR7 mQHup0NFF26XMX5KJrQZUWmoYN6JlofJ+xYLoZJM68vzEVhri5hfqZvKT4aI2CTUFsRJ pU0Q== X-Gm-Message-State: AO0yUKWBJ2HYSASigonaE3WJ7fn6lVSTBpMnxtaxb6zdNrWuV3+anw8r NmKirpP2oET4Vt2/YKEX6HQs+RbYULRAtL3x8uwaVTj6JkOPMv/ucJOTZyykKsi7stc6S8lO6mC FH2cXjvczmD695rLZXizF2cEc X-Received: by 2002:ac8:5dd0:0:b0:3b6:425d:d5ca with SMTP id e16-20020ac85dd0000000b003b6425dd5camr12051177qtx.24.1675067168816; Mon, 30 Jan 2023 00:26:08 -0800 (PST) X-Google-Smtp-Source: AK7set9MV6u8uT0jvPDJaSJ5nfhgUrilLWyrJYf9jx8nwDH/LcG7AI2rY5/eK1DiWBX55qVSUYdn6A== X-Received: by 2002:ac8:5dd0:0:b0:3b6:425d:d5ca with SMTP id e16-20020ac85dd0000000b003b6425dd5camr12051162qtx.24.1675067168560; Mon, 30 Jan 2023 00:26:08 -0800 (PST) Received: from gerbillo.redhat.com (146-241-113-28.dyn.eolo.it. [146.241.113.28]) by smtp.gmail.com with ESMTPSA id h6-20020a375306000000b006fa4ac86bfbsm7612982qkb.55.2023.01.30.00.26.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Jan 2023 00:26:08 -0800 (PST) Message-ID: Subject: Re: [PATCH] selftests: net: udpgso_bench_tx: Introduce exponential back-off retries From: Paolo Abeni To: Willem de Bruijn , Andrei Gherzan Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Shuah Khan , netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 30 Jan 2023 09:26:05 +0100 In-Reply-To: References: <20230127181625.286546-1-andrei.gherzan@canonical.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.3 (3.46.3-1.fc37) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2023-01-27 at 17:03 -0500, Willem de Bruijn wrote: > On Fri, Jan 27, 2023 at 1:16 PM Andrei Gherzan > wrote: > >=20 > > The tx and rx test programs are used in a couple of test scripts includ= ing > > "udpgro_bench.sh". Taking this as an example, when the rx/tx programs > > are invoked subsequently, there is a chance that the rx one is not read= y to > > accept socket connections. This racing bug could fail the test with at > > least one of the following: > >=20 > > ./udpgso_bench_tx: connect: Connection refused > > ./udpgso_bench_tx: sendmsg: Connection refused > > ./udpgso_bench_tx: write: Connection refused > >=20 > > This change addresses this by adding routines that retry the socket > > operations with an exponential back off algorithm from 100ms to 2s. > >=20 > > Fixes: 3a687bef148d ("selftests: udp gso benchmark") > > Signed-off-by: Andrei Gherzan >=20 > Synchronizing the two processes is indeed tricky. >=20 > Perhaps more robust is opening an initial TCP connection, with > SO_RCVTIMEO to bound the waiting time. That covers all tests in one > go. Another option would be waiting for the listener(tcp)/receiver(udp) socket to show up in 'ss' output before firing-up the client - quite alike what mptcp self-tests are doing. Cheers, Paolo