From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpdh19-1.aruba.it (smtpdh19-1.aruba.it [62.149.155.148]) (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 4B602442138 for ; Tue, 29 Sep 2026 06:36:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.155.148 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790663814; cv=none; b=mKJYRz901IpNAu3hT1GUX6UMMMvQUoaRml+/hGytBBlfRc2UZZfqWhjiWAoCeASeFPTqEdWAO0de4Ji776cLLSf2LK6bmogzJFSXuyY2htu7ScLEMBRaPB3I7B/AGPNaJTZVsCxXeq/H9SOckfUlTG12qQP93JkVXaVMlEgianI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790663814; c=relaxed/simple; bh=XApIJdJt9qvKv26L7T5HvfW0f+l+v5xatimMnJLKgZs=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=US37L5Vebron1Mn8EwQmsg3nuuklkP4Yq7ageNb6xk/aYuNJk5gjnw3kH4qfHf+aLTgVZ13PonDHkVsT9WDaR91aJoUoB0DuTrBnnv6YkjgCC9vT3T2JLNfOROFXNmjiHpj1c5wdq+Sx7zBNkU+ReSTb276SGcoidc7Xh1ZdA74= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com; spf=pass smtp.mailfrom=enneenne.com; dkim=pass (2048-bit key) header.d=aruba.it header.i=@aruba.it header.b=Iu1XawDZ; arc=none smtp.client-ip=62.149.155.148 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=enneenne.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=enneenne.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=aruba.it header.i=@aruba.it header.b="Iu1XawDZ" Received: from [192.168.0.186] ([101.57.122.26]) by Aruba SMTP with ESMTPSA id BRPIxrKOe5bAIBRPJx8VQb; Tue, 29 Sep 2026 08:33:41 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1790663621; bh=XApIJdJt9qvKv26L7T5HvfW0f+l+v5xatimMnJLKgZs=; h=Date:MIME-Version:Subject:To:From:Content-Type; b=Iu1XawDZry/JBK4GcI45mZ2n3wW4ZzyByRwTuGYX1Dgj/Lmc7knxEgpxJkIBRHuv2 K3VXCtwaCvdJiOaXb8hoiqfCIParx5pFus9v8ipHQGr3LCfYp5pcL8upd8CSlkSj46 yiI9a2By07k83BStTOoh7owxdY7eKHFOj1QZkuRUMW2UWjyyu+iAUCWjA6ldrGxxw5 jzUs8SjHcr/Q/DcDAbLmJexXK1ObxJ1rpI2zCHFUVl5m9DAx+LQGU+AJzBhh6t3z88 qtjaNJSjCRpQ+5FAYMJnhLWODvwHYNUEAM3qfzKVAu2cNS/ibsqO70T82n1ScylEeM ajryb+hmSThfw== Message-ID: Date: Tue, 29 Sep 2026 08:33:40 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 2/4] pps: Drop the !NO_HZ_COMMON dependency from NTP_PPS To: David Woodhouse , Richard Cochran , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , John Stultz , Thomas Gleixner , Stephen Boyd , Miroslav Lichvar , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Alexander Gordeev References: <20260829210041.40649-1-dwmw2@infradead.org> <20260829210041.40649-3-dwmw2@infradead.org> <7098f5d2-043d-464a-82d9-a105e4000c02@enneenne.com> From: Rodolfo Giometti Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfBXYAjp0HtUnk1MTaqBjy0aHW1KxuibbGGMZo0NbDhrE3eQ/pf63AhywT1qaFog9Ez/XFpIdeMetO0rMsnWo31fdvvhosQ0iav2dU5jaZ7mq9ccVCitT owtxeWh/Kf3uuP5dxziWwo1a0A8YRDEwVSM6AM5PZvWgFDpedMpDz8OHFBjCwxMmkZolCF5kKQW9A2yefEOpvs1c+U338STq6RIASwnDX/wpvSoGXLmysIBm NgwTLBeb8+cO+Qj8Kvvqa92J02ksojOB+DTnUmdtiXlQWbdgOoxhLXCL4Xw9pwm6BrTgAY9B/MqhzXtxFGD+4NyUUj1qIaTYJ4V4493fYAzHio3OzcmB01vw lzuuG9EeUBeb8Uv/XgW6G0xqLsT+nNgm1GzncSuXiKmWcKKVVemSGXBCdNwfYnQqcRjA4Jdu4q6TNbq/YodvSDd9+PJcvdXSAQ9dRM2lBtQG2pesGa8M3UbK GRUmfO820XxCvJHKcsKQ8UCGTt4y19yG65OWM0IJ79Z6PGlare33lSadW5LNgnQJY9vLxoPODLfSiEVhPB0lR96tt7eLHdPkTQZqVoDqrR73l73uYduFCyBE 8TCzwzQUKiMzlNkoMgve0HLJ On Mon, 2026-09-28 at 20:28 +0100, David Woodhouse wrote: > Yeah, working on that now. My first soak test on the nohz_full build > didn't have nohz_idle, so it wasn't really very tickless. [...] > More data, and pretty graphs, when I'm confident of the results and have the > A/B testing. Thanks, looking forward to it. For the A/B comparison, could you also report the hardpps side, i.e. the PPS offset, jitter and stability as returned by adjtimex(), on both the tickful and the tickless kernel? ntp_error shows that the correction works; those show whether the PPS discipline converges as well as it does today, which is what 2/4 is about. Please also state whether the pulse comes from a real GPS on a GPIO or from the vmclock 1PPS in 4/4. > The ntp_error being corrected is still two orders of magnitude less > than the jitter on the IRQ, mind you. Worth a sentence in the commit message too, I think. Ciao, Rodolfo