From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2834551006 for ; Fri, 26 Jan 2024 09:53:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706262823; cv=none; b=MFuFOQ/rSLjc/s4LJzsOtIPUy0cy1MAFLU7z3AK6lRzXJ0PoIPpiDSpYkwKTswKDO5ZK0ERSunfSvkBDXVeS+3dWlhMpKJxPvsZtlAzBDLYAUztVwZyv1Sc69PmXODC8zKTdPBua3KdpBouz3RjFHIf4l6aGEopIQcOdz5qmM3w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706262823; c=relaxed/simple; bh=8Beg/GZD3NOgsphJ4h0Ay/3nnecCyIqKIgWBUUliB9A=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=brZ5Cq5DEjJHJBL6wS9A1hviTXyuYBOYfCjZN5XZho+OLPLoVaeSjihPO/KdJNjRCYoDYE5clcGmB0dq/E8ED1vm4tTQK8RpC3NBJ/mk5t1d8TcP090vrQ+TOg+oFpgFiQEDZBt0rezNccSdcSZRxOF+MfMD3PN6v19YLWO4koc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=V2opWXVp; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V2opWXVp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706262821; 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:autocrypt:autocrypt; bh=Tq7If854ckovFMW4ba/uZhxfAY6UAi/uFwIpsE5dy3Q=; b=V2opWXVpMwW2UxpnZ6O+BQ4eAbqNa0g/ZJMQvxk8BHxdTffZhdanceicVR/bu5MfZyp0ti EWYIcIFiBN6HWMYCidNw8+DrY/KTIsR6uvaJNyYBuzrvcN22MmXLkh547jc/+KctcjMmr9 DUwomkornA6Yf8L6G1lou+IE/63Ga6o= Received: from mail-lf1-f71.google.com (mail-lf1-f71.google.com [209.85.167.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-646-X44wdb1FMHan5ntm_MgJMw-1; Fri, 26 Jan 2024 04:53:39 -0500 X-MC-Unique: X44wdb1FMHan5ntm_MgJMw-1 Received: by mail-lf1-f71.google.com with SMTP id 2adb3069b0e04-51025c44076so43353e87.1 for ; Fri, 26 Jan 2024 01:53:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706262818; x=1706867618; h=mime-version:user-agent:content-transfer-encoding:autocrypt :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=Tq7If854ckovFMW4ba/uZhxfAY6UAi/uFwIpsE5dy3Q=; b=cMY6PvZY9OpT4uTbQ/vGCemBlc5eq/EqTb5eGRvDnsuZwHHxcSjkJtxTFdNM5f7c2r DoSKes+wZuDoYnpjIXyMLWgoSeJBZ41euRYIeh2XPCOh9kQIP4Wcl5f0HvwLC2hPGEUh aCsERPIMGdQSUMPaeZMKlvNycGs0mduVjSqIVWovtn1T/lXhU331JggFsDSgzQ5zWaMk NEfWYF8UGNharo98x0HFMJDlU4E2mACYB65XG7hbChVJ+UnpOgqIxhGX23hIcgCCE3zX K+aV3Ms3rSV9LrReu/YUBufALFKam6eyCE+AFwYuTeEFX8r/Cuu9uPcfnGHj1kpR57bI joYw== X-Gm-Message-State: AOJu0Yx1E/UJzy5QaXwHepdeSyVm5xao5cFukXIMxtVnySq+kj0+vYLC uFEsWfLi5SoXAdpUjmU64TZBwjWZChhEAI+NJ6fn4OGso7QHAOhlRLsQCdmDfDzWnln3s6of9LC uBda3azlVQPvPIvK2C3flwMDD1HF4PoOmeTbnMb58P1kj8izYpCBGTZhmINR1Hw== X-Received: by 2002:a19:910c:0:b0:510:544:792 with SMTP id t12-20020a19910c000000b0051005440792mr1487171lfd.0.1706262817878; Fri, 26 Jan 2024 01:53:37 -0800 (PST) X-Google-Smtp-Source: AGHT+IGawM3XAMzPd555Z3AeHDwlygdttxmSyYn/Pr3NyGvEwDEf4DPuBAUhrHaOT88R03Dsm2o54A== X-Received: by 2002:a19:910c:0:b0:510:544:792 with SMTP id t12-20020a19910c000000b0051005440792mr1487153lfd.0.1706262817507; Fri, 26 Jan 2024 01:53:37 -0800 (PST) Received: from gerbillo.redhat.com (146-241-246-68.dyn.eolo.it. [146.241.246.68]) by smtp.gmail.com with ESMTPSA id e12-20020a05600c4e4c00b0040ecea22794sm1337797wmq.45.2024.01.26.01.53.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Jan 2024 01:53:37 -0800 (PST) Message-ID: Subject: Re: [PATCH net-next 1/4] selftests/net/forwarding: add slowwait functions From: Paolo Abeni To: Hangbin Liu , Przemek Kitszel Cc: netdev@vger.kernel.org, Jay Vosburgh , "David S . Miller" , Jakub Kicinski , Eric Dumazet , Liang Li Date: Fri, 26 Jan 2024 10:53:35 +0100 In-Reply-To: References: <20240124095814.1882509-1-liuhangbin@gmail.com> <20240124095814.1882509-2-liuhangbin@gmail.com> <31c8afe0-86fe-4b39-ba7d-a26d157972c9@intel.com> Autocrypt: addr=pabeni@redhat.com; prefer-encrypt=mutual; keydata=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 7ZxN9ZsDL38qVIuFkSpgMZCiUHdxBC11J8nbBSLlpnc924UAyr5XrGA99 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 iWjoCy8L35zPqR5TV+f5WR5hTVCqmLHSgm1jxwKhPg9L+GfuE4d0SWd84y 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 sD2W1U7eyLdm/jCgticGDsRtweytsgCSYfbz0gdgUuL3EBYN3JLbAU+UZpy 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.3 (3.50.3-1.fc39) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Fri, 2024-01-26 at 17:22 +0800, Hangbin Liu wrote: > On Wed, Jan 24, 2024 at 02:25:57PM +0100, Przemek Kitszel wrote: > >=20 > > > + echo -n "$out" > > > + return 0 > > > + fi > > > + > > > + local current_time=3D"$(date -u +%s)" > > > + if ((current_time - start_time > timeout)); then > > > + echo -n "$out" > > > + return 1 > > > + fi > > > + > > > + sleep 1 > >=20 > > I see that `sleep 1` is simplest correct impl, but it's tempting to > > suggest exponential back-off, perhaps with saturation at 15 > >=20 > > (but then you will have to cap last sleep to don't exceed timeout by > > more than 1). >=20 > Do you mean sleep longer when cmd exec failed? I'm not sure if it's a goo= d > idea as the caller still wants to return ASAP when cmd exec succeeds. I think exponential backoff is not needed here: we don't care about=20 minimizing the CPU usage overhead, and there should not be 'collision' issues. Instead I *think* you could use a smaller sleep, e.g. sleep 0.1 and hopefully reduce the latency even further. Cheers, Paolo