From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpcmd04132.aruba.it (smtpcmd04132.aruba.it [62.149.158.132]) (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 B601A4EFFDF for ; Mon, 28 Sep 2026 16:44:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.158.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790613886; cv=none; b=ga5bA0vVzEMFw2u1BVgsprVgLmKB2bdSTcOeCFi3cl0EtcE5xTgXM7yAoZOMu7VqYplikhjv+hccHEvcQdRJFJ7ELJIgNa9L/HxQyd+sNqeIa/468caMgnCuK1YtB+BBPMCn01hIIO62lnERC5XrAkBGSTjeFNVEhrH2AdCox5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790613886; c=relaxed/simple; bh=4Ebey87VEC2Sy1nN53gKuST7JmuOLoWCUaBl76N3ojQ=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=lm79voNivOztij3skciYEqNO2019Qw+btI6LDe9pZVvQK9KeTkdY0yr6jO3NFiu6yhmy3LI5EdicBRhidZB5absfUKbKnhACtNdmAFcQPg9Xp+Pp3WPdOtqL6U5gDGLELzXYNsAGCS9lg31k8OqcV1MMKRVbvQF9RQdP6e4nSnE= 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=np0LPM/W; arc=none smtp.client-ip=62.149.158.132 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="np0LPM/W" Received: from [192.168.0.186] ([101.57.122.26]) by Aruba SMTP with ESMTPSA id BEPxxBNV9rqLfBEQ3x8lsz; Mon, 28 Sep 2026 18:41:36 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1790613696; bh=4Ebey87VEC2Sy1nN53gKuST7JmuOLoWCUaBl76N3ojQ=; h=Date:MIME-Version:Subject:To:From:Content-Type; b=np0LPM/WkDSAtEezav8whPFdLtieMzaMNWxe5XDIuy59/zMxjf1uXmsx76jBHZyIU XASgZr715wy2wcTprjK+sJdaoVNLgQOJr08PVdKTkoh27NU09ZAhlPDz7bPsuxSSRB Sqgl6ZnFdpw3TfJdsnmRot61ARFJFYMamJADGYp2hilVbC0HEVBe7h3KpdbxgDiRDh ZQW30gJsDM4HGGHd0HKbjD1WRCAxMss7vDN0TSZKWURqRXPk1uZW2eNdTb49f4sH97 Y/kF1wDx8WE/CRiRGNbmYNrPG32X23/bMzvzuaBcqkcYJgHwjstA627jbIFGGMC+cu U52zIX3PFjKUg== Message-ID: <7098f5d2-043d-464a-82d9-a105e4000c02@enneenne.com> Date: Mon, 28 Sep 2026 18:41:35 +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 Content-Language: en-US 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> From: Rodolfo Giometti In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CMAE-Envelope: MS4xfNDYwTfEqsC4GpI7TTFi+oSbTqe4C5mywxys7oqOfGTrjX6ZCyz7VeIGc99bxfoRmuc8ytCjWSYrAUsRAofSoZyce/2/oZ7C8orHAsynP5Bh9mv5GMvh DRDonXZsshHRO4ghgdRBZzzcRVFsNx5QCpCNFsjXteFdhAte+QsaxqkKa+AZKJo+JGJwP4aeNAHwjCIWbBEV6CKAf13Av5tIn0DMiyfJWR/2t3j6saUaQLqn xwujUylWjHyS98D1+TxF/eV7fxrP2hfwKw7rev0mQxOXHHmDxWRlMqCGOW3ZgyfmJjpy011IC9Sr6KTFcdjTVmK1XQYZ9sbHo+9CCG6/CeNJKRw9pgtJ71kZ IWRT26u1wkUFDlxyZK2T38rbXrbjiI6UlbH/eP0xK2E6HDm6Ua+KVSSo8i/hExgjdOFXZZWuhtC/jd0KjwlrTudarVInilJt3l09+LyIDMt9BRTTHDiNajCS qxmMkym16Atzvtym3u9NiG8oW0cKb67hyQEMuFc9s7F26GIwbyQIZ4DJ1f6g2mApnZ0ZNp2klXeYZR7FDIaHBsfSlsIYTQmAFV0bFu2v2mmw7BREIMrX/POt 83G5UwDbE5DfdeHq9cBUqSGD On Mon, 2026-09-28 at 14:37 +0100, David Woodhouse wrote: > But I can *simulate* it, by running a virtual machine with vmclock and > knowing the precise relationship of counter to real time that I'm > *telling* it to discipline against — then checking how it did. Your "no > independent reference anywhere" is my "I'm actually testing the part I > want to test" :) What it cannot show is the thing this patch actually enables: hardpps on a tickless kernel driven by a real PPS source, with its jitter, its IRQ latency, and the CPU going idle between pulses. If you (or someone on Cc) can run it for a while with a GPS PPS on a GPIO and report how the offset converges compared with a tickful kernel, that is the test I would like to see mentioned in the commit message. If not, please at least state there that the validation was done with the simulated 4/4 pulse only. Ciao, Rodolfo