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 E974B2DEA79 for ; Tue, 23 Sep 2025 08:02:11 +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=1758614533; cv=none; b=i7SbO2dUOU2nYxRpshHaZxcn1mr1WOM14CwIFZWqFLXWFWgvR4j5Asf6H341KRVF6W9MZ1HfZ/oFgu/J3hPuySkUBFeDP5SXaG+kDTBmMcgB81DbVvELk46UBw5DNsrj/PDUHNgLnlWlxLO7zgwct1nWceUWXT+cDbtKB5ldKbQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758614533; c=relaxed/simple; bh=scPLBheLCFrb9aBaepkVLX57LEpK4csVqkaXTsIsrbk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=up+97hhM+u8UgPyiuX9oqMbJqx9yzwQ6fC15o+ACGK9/LF5b9n3h+1BCjk6gZsXqElwqUmjVWtnTPKqXCikAAgsMGaY+QIFB/l/Af/nf31ILtAE98pcfJfIIPfzrbmv9njgyXofZwo0TJnXEjlvX3mJ53lmpAacjkN9t09iJlo8= 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=C9lErGtJ; 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="C9lErGtJ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758614530; 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=TOkyzE0c1T3gu5dI+oIIOizv6pKHsRXJTQzDXcjJAJc=; b=C9lErGtJ9jYQoV0ET/UhXraL6iY9ftTfATlcjG/m5KOobURK7wyNXsSaFiQqw7J9a1MZqh kHRbxM3cEoJkmIJzaBIK7RRqFLNFU2FQuD1dKwp43wZQQe8602/XEwkGCo1VG/mt9+gNg4 UdZHiUdpfl2VL0QPPHVYZ4Z6z0btVBg= Received: from mx-prod-mc-05.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-436-xVpVznRlPtaQEpkQYh-fBw-1; Tue, 23 Sep 2025 04:02:06 -0400 X-MC-Unique: xVpVznRlPtaQEpkQYh-fBw-1 X-Mimecast-MFC-AGG-ID: xVpVznRlPtaQEpkQYh-fBw_1758614524 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7A3C21955F45; Tue, 23 Sep 2025 08:02:04 +0000 (UTC) Received: from localhost (unknown [10.43.135.229]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B9A7D195608E; Tue, 23 Sep 2025 08:01:59 +0000 (UTC) Date: Tue, 23 Sep 2025 10:01:57 +0200 From: Miroslav Lichvar To: Kurt Kanzenbach Cc: Jacob Keller , 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> <87ikhodotj.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: <87ikhodotj.fsf@jax.kurt.home> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On Fri, Sep 12, 2025 at 11:04:24AM +0200, Kurt Kanzenbach wrote: > Sebastian found a machine with i350 and gave me access. > > I did run the same test as you mentioned here. But, my numbers are > completely different. Especially the number of hardware TX timestamps > are significantly lower overall. > > Without the patch: > > ./ntpperf -i eno8303 -m X -d Y -s Z -I -r 200000 -t 10 > > NTP daemon RX timestamps : 0 > NTP daemon TX timestamps : 565057 > NTP kernel RX timestamps : 100208 > NTP kernel TX timestamps : 281215 > NTP hardware RX timestamps : 882823 > NTP hardware TX timestamps : 136759 > > With the patch: > > NTP daemon RX timestamps : 0 > NTP daemon TX timestamps : 576561 > NTP kernel RX timestamps : 99232 > NTP kernel TX timestamps : 255634 > NTP hardware RX timestamps : 868392 > NTP hardware TX timestamps : 135429 ntpperf sending 200k requests per second for 10 seconds is 2 million, but the sums of RX or TX timestamps in both your results show it handled only about half of that. The CPU seems to be too slow for such rate in either case. I was testing it with an Intel E3-1220 v6 (4 cores, no hyperthreading) and I set "-r 200000" to roughly match the maximum rate my machine can handle before the patch. Can you please try adjusting the rate to minimize the loss in the test without the patch first? > What am I doing wrong? Here's my chrony config: Your config looks good to me. Here is mine, but it is functionally equivalent wrt this test: hwtimestamp i350b clientloglimit 1000000000 local allow > > |########## i350 NTP performance regression test ########### > |local stratum 10 > |allow X > |allow Y > |allow Z > | > |hwtimestamp eno0 > | > |clientloglimit 134217728 > |log measurements statistics tracking > |logdir /var/log/chrony -- Miroslav Lichvar