From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CD4BE36D9F0 for ; Wed, 4 Mar 2026 18:40:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772649621; cv=none; b=dUr4spVSPVhv/IXjhF4A1IgpHSxYHDqNbiLnuA8tqMhuaYljLDy5P67xWYq2RTCLbwCfVa0yrtgclQ7iuhOPB7LUymIHv/LI6qdetN63lXb2BnXIGrhDDteZRrX2JAHkOxdWWqIorsax/BgvnvAtOkvRFynxmIyf1zmDzvJZT2U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772649621; c=relaxed/simple; bh=fGEc5UlG43DbXTqmVzOnJd0AyVjuo+KNAAzK2N7+0OI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=FVLlHSRlXt1Im3/Y4BT0E/2ofAyu6MADVuZDuiIBRlQmk7WDc78oJ2EHRT7ckqns6r40NTp6zR5smz8cBN3Wf+eAu2CWaeOx/rFCxrbt4s3Vp2lTzDdy0dxzv8782mOqBNtIMzPbtSB/rTsRzcPHGWOis50NuycP+DB3dk2eyvY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UB/ujNGX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UB/ujNGX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3772C4CEF7; Wed, 4 Mar 2026 18:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772649621; bh=fGEc5UlG43DbXTqmVzOnJd0AyVjuo+KNAAzK2N7+0OI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=UB/ujNGXsXWM562CRp9UcH64wc2mlm/8rBTk8eOMaVRy8hGUt7BbJiPLfwAbNfktu m1StaCvMpWlkfrSBCUpf3/SKPHIyLrTacHEVRd5HgNm8BeCRn5P4dUp/7kWyVlySRv njrbjaIX6iZtti5zcbG2UvuLOk4KVrNaHFbPDtCQ2c9LW9Zg9PNDkeZUM8iykAqVem rSd7wIzw+VB4NxkflCZ7uQ5hkfBsWHOKcS9bdO+912iPjxqluizt+Z4xPx4WXn+PNh 7DNlgtbd+g+azO0My5osb8xFp3R1UZ3yLZ4pKuh/iIT+z4WXih+yFoNxkmtuOoD7q/ 5Od9tKzUmsrbA== From: Thomas Gleixner To: Nathan Chancellor Cc: LKML , Anna-Maria Behnsen , John Stultz , Stephen Boyd , Daniel Lezcano , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , x86@kernel.org, Peter Zijlstra , Frederic Weisbecker , Eric Dumazet Subject: Re: [patch 20/48] x86/apic: Enable TSC coupled programming mode In-Reply-To: <20260303213027.GA2168957@ax162> References: <20260224163022.795809588@kernel.org> <20260224163430.076565985@kernel.org> <20260303012905.GA978396@ax162> <87jyvtyo6o.ffs@tglx> <20260303173809.GA1114907@ax162> <87ecm0zmsf.ffs@tglx> <20260303213027.GA2168957@ax162> Date: Wed, 04 Mar 2026 19:40:18 +0100 Message-ID: <87h5qvsajx.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain On Tue, Mar 03 2026 at 14:30, Nathan Chancellor wrote: > No problem and thanks for the explanation! Unfortunately, in further > testing, that diff appears to break booting my two AMD test systems, > which had no problems with the current series. The output from that > previous dmesg command from both systems on a vanilla next-20260303: > > [ 0.000000] tsc: Fast TSC calibration using PIT > [ 0.000000] tsc: Detected 3792.761 MHz processor > [ 0.061853] clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x6d574392f2f, max_idle_ns: 881590904565 ns > [ 0.332910] clocksource: Switched to clocksource tsc-early > [ 1.368506] tsc: Refined TSC clocksource calibration: 3792.899 MHz > [ 1.368521] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x6d584a46b0d, max_idle_ns: 881590977212 ns > [ 1.368849] clocksource: Switched to clocksource tsc > [ 4.497901] kvm_amd: TSC scaling supported > > [ 0.000000] tsc: Fast TSC calibration using PIT > [ 0.000000] tsc: Detected 2994.309 MHz processor > [ 0.179828] clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x2b29459826f, max_idle_ns: 440795319985 ns > [ 0.452947] clocksource: Switched to clocksource tsc-early > [ 1.485796] tsc: Refined TSC clocksource calibration: 2994.372 MHz > [ 1.485810] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x2b29812ce43, max_idle_ns: 440795323173 ns > [ 1.486231] clocksource: Switched to clocksource tsc > [ 7.870821] kvm_amd: TSC scaling supported Borislav has observed that too. I send out a fix in a minute. Thanks, tglx