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 055DC2C11C4 for ; Wed, 20 Aug 2025 06:54:21 +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=1755672863; cv=none; b=O4OgmD8wKOXLZmy0MUqaEmX9A4Hz5dpLcGZtwH9ZzO7p5HE1WdxqmQy5rxw9w5kFPhIU+9BECq2Q+NK+qt1+tBZim6yT5Oesu5UItFVMkwWg559sQ/yGBIBvRQMd8LAriP24uqFvcP+g+07n4yDjXrLY9IC59GOJHRnr7fyRa5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755672863; c=relaxed/simple; bh=C7FGJEn9utV4DVIxMBnuhS0fIHB/EBeIFop+TFsP6/s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LoCrK2EbM9jEzjIdMGzPz0ECgr9kx8sPtAb/bxChjE7sTKIUcXIIk395ROAZyac49fSEx0cRVwGoCprG/t5bnsZ+JaigmZBnB6krAqBgnZ2RrHUWd54MDG2jl9K31xo3Vyufx6x5IBhleR31+Al5LfJH9k43efYxtHgklf3d2e8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=OVZX+l1y; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="OVZX+l1y" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755672860; 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: in-reply-to:in-reply-to:references:references; bh=yovFcx2lS/jztUpVbcF86Ft2OX16ePIPJO/lfVq9oj8=; b=OVZX+l1y4Yn+5W5zRhdVvDfjoyr2RHv8R7gG1xfI3VtBmhnVUZ7Zclcb4cpXZhhdGyT4tW FgftEk7UsD9GjHmEUc5Q4GE199L6ARwjBUV/LLACxv4hTE/TkcyPYjCdBKj6rlqzXJIwNH bL2wuoxrpPZQuLElitMQBl3bFTj/u3Q= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-672-UBGOA6hBNt6Wf8X1tSnt6w-1; Wed, 20 Aug 2025 02:54:15 -0400 X-MC-Unique: UBGOA6hBNt6Wf8X1tSnt6w-1 X-Mimecast-MFC-AGG-ID: UBGOA6hBNt6Wf8X1tSnt6w_1755672853 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EFDCF1955D69; Wed, 20 Aug 2025 06:54:12 +0000 (UTC) Received: from localhost (unknown [10.43.135.229]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 04DE1180028B; Wed, 20 Aug 2025 06:54:08 +0000 (UTC) Date: Wed, 20 Aug 2025 08:54:06 +0200 From: Miroslav Lichvar To: Kurt Kanzenbach Cc: Tony Nguyen , Przemek Kitszel , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Richard Cochran , Vinicius Costa Gomes , Sebastian Andrzej Siewior , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org Subject: Re: [Intel-wired-lan] [PATCH iwl-next] igb: Retrieve Tx timestamp directly from interrupt Message-ID: References: <20250815-igb_irq_ts-v1-1-8c6fc0353422@linutronix.de> <87ms7vs6vk.fsf@jax.kurt.home> 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: <87ms7vs6vk.fsf@jax.kurt.home> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 On Tue, Aug 19, 2025 at 04:50:23PM +0200, Kurt Kanzenbach wrote: > Installed ntpperf on one machine and chrony (v4.6) on the second. In the > chrony config there is 'hwtimestamp enp1s0'. I did run the first example > in ntpperf's README with the following results. 'rate' seems to be > higher with my patch applied. Anyway, your ntpperf output looks > completely different. What parameters are you using? I just want to > reproduce your results first. > > root@cml1:~/ntpperf# ./ntpperf -i enp1s0 -m 6c:b3:11:52:39:15 -d 192.168.123.1 -s 172.18.0.0/16 -B -H Interleaved mode needs to be selected by the -I option (instead of -B) in order for the server to enable SW+HW TX timestamps for the responses it sends back to the client. My ntpperf command line also had "-x 1.05" to increase the rate in smaller steps and "-o 0.000000500" to print the offset between the server TX and client RX timestamp instead of the offset between server's TX and RX timestamp (response time), but that requires the NIC PHCs to be synchronized to each other over a different network link and the -o value to be calibrated for the delays in timestamping and cable. It's not important for this issue, no need to bother with that. > * ntpperf with igb patch applied > 129721 12972 0.00% 0.00% 100.00% 0.00% +7934 +49386 +229427 17600 > 194581 16384 0.00% 0.00% 100.00% 0.00% +10760 +54961 +248325 18860 > 291871 16384 0.00% 0.00% 100.00% 0.00% +13207 +57193 +248870 16908 > 437806 16384 25.42% 0.00% 74.58% 0.00% +211479 +275061 +703480 20529 > > * ntpperf without igb patch applied > 129721 12972 0.00% 0.00% 100.00% 0.00% +2670 +14699 +242395 6692 > 194581 16384 0.00% 0.00% 100.00% 0.00% +2520 +19712 +329254 9571 > 291871 16384 1.37% 0.00% 98.63% 0.00% +2818 +77396 +15480693 182286 > 437806 16384 24.69% 0.00% 75.31% 0.00% +108662 +246855 +2306431 38520 Those results look the same within few percent, as I'd expect with the basic NTP mode (-B option), which doesn't enable server's TX timestamping. Normally, I see larger differences in subsequent runs in the same configuration. -- Miroslav Lichvar