From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpcmd11117.aruba.it (smtpcmd11117.aruba.it [62.149.156.117]) (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 8A2404BE434 for ; Thu, 1 Oct 2026 08:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=62.149.156.117 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790843029; cv=none; b=K2ABmb2FMBmiMbti35L+rGpBzaLwSgVLjioReF169NeE/15SH8FkGUfG62x3JxAZhmBEVIIQRg1xNTZ5Pj7qGPXJ83PiGLs9ownANe2YA6DVP0PNh8vuq791DRUCaad1h8OK0mho13MJluIww/Tbu9eEeEI3jve661Nkl8ZZQK4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790843029; c=relaxed/simple; bh=5ii2wsmim5NNuQYKQidppV2R7J5iURxqkVb508DATbo=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=h7GAyT8Ze69jOdXD62CqDLNTG76ugp4LeYPkVuLyQKAAF8bjfYVCZjdrZj+1lkFzu0X6sjw3hl7OuYV3H1WL8iz/o9xsXQzg4Cll4WcXCntMki3+M03WdvK2iRzGJSRXRyZ8CH52wQU0dYaj8tHGldq8r0Xd7whVx4Fp3+KJMFc= 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=DcRHM2er; arc=none smtp.client-ip=62.149.156.117 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="DcRHM2er" Received: from [192.168.0.186] ([101.57.122.26]) by Aruba SMTP with ESMTPSA id CC1oxVAz8l4ytCC1oxmhmk; Thu, 01 Oct 2026 10:20:34 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=aruba.it; s=a1; t=1790842834; bh=5ii2wsmim5NNuQYKQidppV2R7J5iURxqkVb508DATbo=; h=Date:MIME-Version:Subject:To:From:Content-Type; b=DcRHM2erSauuABoy5m3lY34wozJdaHok7MToYxoY5xKC5xVxipZY/h8KV+BkNlBhI R5cZweUWjz9rWhrqwSbc9pep2lHEGwLjqdSlscqxvbHi0plmDFQM9s4AoWr3T36h9G UJBusN9ZhyfnhjJDsmlFKVSkxpVye4al8ocX6ZH4LqHS02+Mdwlwk18zi8x0vzYYdN 0u/EuVhaH2kauIRM+NFmVgmZcWLiALpMqv9wEcrBSQ/tQ+bGocjvbMm9ffegHquWsT UdLRGaet8x0gHFDZYk4Z6TBR7+8ySTZg49JO2Rp1PtUFp029oHkNpfrfHhYaLjEKz9 xm/6r6gOs0ECQ== Message-ID: Date: Thu, 1 Oct 2026 10:20:31 +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> <7098f5d2-043d-464a-82d9-a105e4000c02@enneenne.com> <7f98cef0918465e8d6bc9e76d26afb8b12471773.camel@infradead.org> <37ad7bb611c0e79840dfdb5c3706be3430c34bb4.camel@infradead.org> <6a529b5fe8c5bbb664748b85be011f5cf2e6c44d.camel@infradead.org> <14280dde8487260f4c590d49a0297777b690660d.camel@infradead.org> From: Rodolfo Giometti In-Reply-To: <14280dde8487260f4c590d49a0297777b690660d.camel@infradead.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfP2FmQHNkKJ0TJLV9n1zHxyQ0nW5TVhkzauVFFpukSMWwqTh5S198FuvYZDzk+JnNYN9aR3n9hbo8jN1tZt/bWI3oAYJrWULkG7Uie38M0nNZIrcOHWf Z8EzphhxTgBS2oD4BDB9jSpebexAOvFz59ZeLYDLiawRiAqE13ztPCtxTCy4vWg6/K+HeNJYCTBOZoQNwU2oW3ZiX2qxwSjH9IXboEcj53TT4CjPBADER7tH K9rhTHvZCendM9l2utQ7m3Aa6a/2PpMv7id0xGdjSOAju1oaVstrlj/qo2mgkYq9r0iHAJoGUfgQ7gQPDW+skc2lFNiarYru7xw0a28iBFLz5C5hNPfEYJun fkGmT+L7COC6z7XP7ffRMH+H/QvO6pEMRsMRYQ6g991S2d6uBbnWiBAuBlwx5n96u1Zh80TlmDMmGw84vGvJTanmu83momVo/xt0rxLKMwp0IxYOzRVEYkM2 iIessap1RDYqsm5SS2By4G90z/FrUkdtTQ2bxPvyTsAi9o6nKyH5xbFp+CkMUey2tDfhwLT3AjTvsF/CFmwdHUv2elgbdfqqnpAXtEmNdfdh6O+cfvFYhbNc etsrLTV2mgrzypWDp25QNZFb Hi David, On 30/09/2026 20:24, David Woodhouse wrote: > On Wed, 2026-09-30 at 15:05 +0100, David Woodhouse wrote: >> [...] But >> I don't think we're ever going to be allowed to do it that way in >> entry.S but the *hardware-captured* stamps will want the same handling, >> so I wanted to prototype it anyway. Hardware-captured stamps are something I'd really like to see in the PPS subsystem. When you get there, I think it should be its own series, discussed together with the raw counter export you mentioned on the 28th, since both change what a PPS driver hands to the core and what userspace gets back. As I said for the export, I'd prefer to agree on the interface first. > We don't actually do *any* filtering. Even pps_phase_filter_get() is > just using the first sample, with a comment: > > /* TODO: test various filters */ > > Looking closer at the actual captures, even Mills's median-of-three > wouldn't save us here when two of the three pulses are outliers. We'd > want an ongoing frequency estimation. > > But that's definitely a problem for another day. Agreed, but I'm interested in it too. Your setup, with the per-pulse captures, looks like a good way to evaluate a filter, so if you or anyone else picks it up, please Cc me and I'll be glad to review it. Ciao, Rodolfo