From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 5AE2C211A14; Tue, 26 May 2026 23:39:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779838758; cv=none; b=cgE2OJi0dfBoPiNmuSVi8qVtw0PWyfea+LSFwJPPH/p2MB0+ZUpZrbnYpsQAWSdKqXhlmR1DWAykCijsHwZG4OotQNDjyAe6Qk4zMJ8/r+lupHWd55UK6bbvb4LNOXNK+d4QT9Pi72ByUdpJCoDEGZfP13ZxFAn2N0uGJLD01/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779838758; c=relaxed/simple; bh=TCwTU/1zxquo1ICvQGvijvVx7xcBdUFAGIdJDxQciVY=; h=Message-ID:Subject:From:To:Cc:Date:in-reply-to:Content-Type: MIME-Version; b=OyNKGA8uyZQ7JwgYIdHgZ+Rmk401/15C1e9sA/Is5QLB97xZGdQKCHHWeaGIW1jUJEY3UzBb9lgoA95j/bTKRwhZChiCXAeJZVeE6evaUq2bbH0006Pq79pQipSaru4IfnJI8BUNrc1dAyTPOp5ff17reKUcO1YOG0ynj3ZPkqE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=casper.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=VAkzVLQH; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=casper.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VAkzVLQH" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=MIME-Version:Content-Type:in-reply-to: Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:References; bh=TCwTU/1zxquo1ICvQGvijvVx7xcBdUFAGIdJDxQciVY=; b=VAkzVLQHfSOmij0iyS2pOPykW+ Kg69pY0fdhrAlJKbSM1QyjhsL+lZ8ZvhOdUsdMsnepK2xbtXiVAQ7glMCv5+mIdUOGtvsjKLBQJWB iCTsx4kHjYdKfC5abhHEFPYBEwoQTr8j9qi7bWBi6ddvLHPhCAZQDNim0oQCDMq+Apz4rjfOc0sLk 53KNDFhy29inYeE79xSKswc9R9li43pdI8Xd0W9Sk+mI4DSabxUmUVYXKuyWgiqyvKlsVM/XRzafa kbBms3dENMjRg7FvY0pnMd0nj+cW1YXqZwTKbWUvYntYiXXo4mmkK5HKlynNq71KbyhpGOgiBPWIP F/W6zdbg==; Received: from 54-240-197-231.amazon.com ([54.240.197.231] helo=u09cd745991455d.ant.amazon.com) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1wS1Mb-00000001fO3-1YUa; Tue, 26 May 2026 23:39:09 +0000 Message-ID: <33a16a3c1d39147b659ebd4f6122461139159cc7.camel@infradead.org> Subject: Re: [patch 01/24] timekeeping: Provide ktime_get_snapshot_id() From: David Woodhouse To: tglx@kernel.org Cc: akiyano@amazon.com, anna-maria@linutronix.de, anthony.l.nguyen@intel.com, dwmw2@infradead.org, frederic@kernel.org, giometti@enneenne.com, jacob.e.keller@intel.com, johannes.berg@intel.com, jstultz@google.com, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org, linux-wireless@vger.kernel.org, maz@kernel.org, miriam.rachel.korenblit@intel.com, mlichvar@redhat.com, mst@redhat.com, netdev@vger.kernel.org, oliver.upton@linux.dev, oupton@kernel.org, peter.hilber@oss.qualcomm.com, richardcochran@gmail.com, saeedm@nvidia.com, sboyd@kernel.org, thomas.weissschuh@linutronix.de, tiwai@suse.com, vdonnefort@google.com, virtualization@lists.linux.dev Date: Wed, 27 May 2026 00:39:07 +0100 in-reply-to: <20260526171222.769770418@kernel.org> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-3rBkcF72l7XaUPBwCLw/" User-Agent: Evolution 3.52.3-0ubuntu1.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html --=-3rBkcF72l7XaUPBwCLw/ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 26 May 2026 19:13:33 +0200, Thomas Gleixner wrote: > ktime_get_snapshot() provides a snapshot of the underlying clocksource > counter value and the corresponding CLOCK_MONOTONIC_RAW, CLOCK_REALTIME a= nd > CLOCK_BOOTTIME timestamps. > > There is no usage of CLOCK_REALTIME and CLOCK_BOOTTIME at the same time a= nd > CLOCK_BOOTTIME support was just added for the ARM64 KVM tracing mechanism= , > which needs CLOCK_BOOTTIME and the underlying clocksource counter value. > > ktime_get_snapshot() is also not suitable for usage with CLOCK_AUX, but > that's a prerequisite to support PTP hardware timestamping for CLOCK_AUX > steering. > > As a first step, rename ktime_get_snapshot() to ktime_get_snapshot_id(), > which now takes a clockid argument to select the clock which needs to be > captured. The result is stored in system_time_snapshot::sys, which will > replace the system_time_snapshot::real/boot members once all usage sites > have been converted. > > ktime_get_snapshot() is a simple wrapper which hands in CLOCK_REALTIME as > clockid argument for the conversion period. That means CLOCK_REALTIME is > now captured twice, but that redunancy is only temporary. > > No functional change vs. current users of ktime_get_snapshot() > > Signed-off-by: Thomas Gleixner Reviewed-by: David Woodhouse Tested-by: David Woodhouse --=-3rBkcF72l7XaUPBwCLw/ Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgEFADCABgkqhkiG9w0BBwEAAKCCD9Aw ggSOMIIDdqADAgECAhAOmiw0ECVD4cWj5DqVrT9PMA0GCSqGSIb3DQEBCwUAMGUxCzAJBgNVBAYT AlVTMRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5jb20xJDAi BgNVBAMTG0RpZ2lDZXJ0IEFzc3VyZWQgSUQgUm9vdCBDQTAeFw0yNDAxMzAwMDAwMDBaFw0zMTEx MDkyMzU5NTlaMEExCzAJBgNVBAYTAkFVMRAwDgYDVQQKEwdWZXJva2V5MSAwHgYDVQQDExdWZXJv a2V5IFNlY3VyZSBFbWFpbCBHMjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMjvgLKj jfhCFqxYyRiW8g3cNFAvltDbK5AzcOaR7yVzVGadr4YcCVxjKrEJOgi7WEOH8rUgCNB5cTD8N/Et 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