From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 40FB57CF1B; Tue, 30 Jan 2024 14:54:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706626465; cv=none; b=kGEVWYLfDsRoN+I0oKUCRlNcaBLOZOpPtCg3+rLAs76hHWjg6UV6NXigdzz8ucl9/HFEuGBhuemTIlTrUGGHETGS0qy6ThcbwXpwyLRhn9cnmDXUMVClcHzMp3klP+wcg+DQXPcoel5G/nah4NKUolhOpp6+CPV7PUHwpnuXbog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706626465; c=relaxed/simple; bh=8cLeOPgTadYKlEfNe21+miLFsUXVR0uTfie/gImXNcs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=snKpfXd5YTnpdCmFWI0sm0EviZTFjnUGw6LUAn+EZ4IHycJtIYHv342fGbOtFEZzdl3ESUKyqK0Gal19pIZT+BclvbhOqFW93z2RtYr0cEfK/Vv8k9MttFtAxZkN54J3aorAWtPE9PcqjNtr5Hhdwp06jdCchNEjbVRBdpYltJs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CYREH9M9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CYREH9M9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD0C6C43601; Tue, 30 Jan 2024 14:54:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706626463; bh=8cLeOPgTadYKlEfNe21+miLFsUXVR0uTfie/gImXNcs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CYREH9M9EYrB13sbo/d2NK3gwFtnk4JZjfedGc9ndsllaZfKk2aJt18OKu948LQrc DuVYpQRsx2HgDVkD6//O9oLo/p1YjGgnPQBuFjxSUfuz/1x79y8ZcXC/j+eTPmuNFJ KaHKinWQic+W0t6BrWjPGSrj7TghNl0weDXI/dSh9+RV30AsAj3KHNT81QuMXcwXLc 2lJqAEN8UD0ww42AMs9tjiF/1N6gRawda0nEXD68bcrk1DNISxz22aQ2uAJo+qDmhR /82WuoPE1i5a+ZmfosbiKG8hr7nYWd04IUBkAPuO+X68PW1Tgho9HWtlXNk3tIsSKs elMqbFBhXnqaA== Date: Tue, 30 Jan 2024 15:54:11 +0100 From: Simon Horman To: Willem de Bruijn Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, edumazet@google.com, pabeni@redhat.com, linux-kselftest@vger.kernel.org, Willem de Bruijn Subject: Re: [PATCH net-next] selftests/net: calibrate txtimestamp Message-ID: <20240130145411.GK351311@kernel.org> References: <20240127023212.3746239-1-willemdebruijn.kernel@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240127023212.3746239-1-willemdebruijn.kernel@gmail.com> On Fri, Jan 26, 2024 at 09:31:51PM -0500, Willem de Bruijn wrote: > From: Willem de Bruijn > > The test sends packets and compares enqueue, transmit and Ack > timestamps with expected values. It installs netem delays to increase > latency between these points. > > The test proves flaky in virtual environment (vng). Increase the > delays to reduce variance. Scale measurement tolerance accordingly. > > Time sensitive tests are difficult to calibrate. Increasing delays 10x > also increases runtime 10x, for one. And it may still prove flaky at > some rate. > > Signed-off-by: Willem de Bruijn Reviewed-by: Simon Horman