From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f201.google.com (mail-pf1-f201.google.com [209.85.210.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F4DA42377E for ; Mon, 6 Jul 2026 18:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783360826; cv=none; b=Uf8plO5Ysfdxrbw3AZ/oQbL3LQ7tdexLAuTgk5TbxfhoEfI1c3PP3bW8YLF+ObVbvh6Om3OEY/XNsuTJSkPjryEAZRc/abET8d0A7dgvv60ucloF61+vplyXhRhdS0yIXsj2cnMkoALtCAJjYBvbqyY+9pkJXNQH8FI2wJiKvPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783360826; c=relaxed/simple; bh=6HvxXL/hPWnIS2ERxITvaZCHswmXyfcfLFJrYY619nA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=gNhVT7yNOWaf8f6HyyvmNOIJdwUlak+vfV7a+MX27zrcY6rCC4V51x8Ig2GHVy1VY8oQC/p5+tzzp2ma5N5DzCZmVOfLfJzbaqHWJU+qV0m+t4jwjknWLhPaAvrTa6a6qQrY2K6GIOqDbA2RlrvZYzaNTQJZDSKK7sIlUYrHO/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=aXRGKFRY; arc=none smtp.client-ip=209.85.210.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="aXRGKFRY" Received: by mail-pf1-f201.google.com with SMTP id d2e1a72fcca58-846f50381a6so2645878b3a.0 for ; Mon, 06 Jul 2026 11:00:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1783360825; x=1783965625; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=eYcfhMi5NCPMduPSvGqKtbO87FaKSq3RfhmI47bcB1U=; b=aXRGKFRYenZRjZGIwSdAJNreLpqh7yKNczUlKghcYwHUg7DkLUY88aYFDcEWam3BTV D0PqKMLZPWjM13nu6q4Ei0eHobHbiyrfJK+iSQWD8Mi8j2AU/T5a2owkWVdIeRZdkjSH NkH9OWVFZrQotIy0W6Vn1juvFI1jWaGVRePRwcH94yRXPLnERxdwpUy93lnN4cBzY3jp vy0ho9+fFAMUv61eu1jqYN7O7N5Y2qZDgZO0GP2eW9sp33Xv8f+9J+8ijifOwwLIy0vW JOM8w0NuKqtUhnOdqszYTSaFuN1y/okEPe9i19RloDZLELXWfdozCSP5nX6RBWdiadfI LhIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783360825; x=1783965625; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=eYcfhMi5NCPMduPSvGqKtbO87FaKSq3RfhmI47bcB1U=; b=bXD0AHA7adugOWk3lGWPTftf2ALZnLuhlVL8wTo2w3tl/EpEfQ7UYqfOtYZyzcM/k7 o6/OJOOo9/bnUrYcrwZ7F8V3g/wUwBWIOmHMDe7bdZhrvOFGwU8c7yNprNJCDdIQySv6 kYWS0PvrzE7JSppaTOXXpS8pFxVZXmdvIIOc2yFCXr7WkR4rtBSvdj2D3AoWnPdwYScn tBvj2yjCBX93U1TuzyKUTZQzdKvCxds2fmP6Qyk7HEKUPtzXk5XxIfYDSXyB2hxgxfE0 Eix88BXGBq/wO9mgspxj5EWo/W5TEAenwBzV+urc+nQslbeQUNL/RYKAX+tDWfdeoqXQ 0VMA== X-Forwarded-Encrypted: i=1; AHgh+RrOTdYY8vaTMiiSUjYTLQINR5mOVWsple++Qy4SZj+Hfl15qcgLg8nfm4PdhsQenAVCUCclw+11Oz376Co=@vger.kernel.org X-Gm-Message-State: AOJu0Yw5TutLM/YWeMMAgtdUvs7C4U+nuCJdzIFQu2QPapftN/dSJ1Ko 6uZux5jIU+9OG9z1tUXjDZLt+4e2yrkw/sm8srZiAEJEo3f9O00GkU9MQXOZCRZUgz39CL0BV/Q 3CY729w== X-Received: from pgam14.prod.google.com ([2002:a05:6a02:2b4e:b0:c92:460e:4f73]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:4307:b0:847:8c6d:2f24 with SMTP id d2e1a72fcca58-84826ec2591mr1691676b3a.56.1783360823962; Mon, 06 Jul 2026 11:00:23 -0700 (PDT) Date: Mon, 6 Jul 2026 11:00:23 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-hyperv@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260701193212.749551-1-seanjc@google.com> <20260701193212.749551-2-seanjc@google.com> Message-ID: Subject: Re: [PATCH v5 01/51] x86/apic: Provide helpers to set local APIC timer period in hz and khz From: Sean Christopherson To: Michael Kelley Cc: Jonathan Corbet , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "x86@kernel.org" , Kiryl Shutsemau , Rick Edgecombe , "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Long Li , Ajay Kaher , Alexey Makhalov , Jan Kiszka , Andy Lutomirski , Peter Zijlstra , Juergen Gross , Daniel Lezcano , John Stultz , Shuah Khan , "H. Peter Anvin" , Vitaly Kuznetsov , Broadcom internal kernel review list , Boris Ostrovsky , Stephen Boyd , "linux-doc@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-coco@lists.linux.dev" , "linux-hyperv@vger.kernel.org" , "virtualization@lists.linux.dev" , "xen-devel@lists.xenproject.org" , Tom Lendacky , Nikunj A Dadhania , David Woodhouse , David Woodhouse , Thomas Gleixner Content-Type: text/plain; charset="us-ascii" On Thu, Jul 02, 2026, Michael Kelley wrote: > > @@ -796,6 +796,16 @@ bool __init apic_needs_pit(void) > > return lapic_timer_period == 0; > > } > > > > +void apic_set_timer_period_khz(u64 period_khz, const char *source) > > +{ > > + lapic_timer_period = mul_u64_u32_div(period_khz, 1000, HZ); > > +} > > + > > +void apic_set_timer_period_hz(u64 period_hz, const char *source) > > +{ > > + lapic_timer_period = div_u64(period_hz, HZ); > > +} > > A string "source" argument is passed in, but not used. Is there an > envisioned future use? Also, this function doesn't output a pr_info() > message like the existing Hyper-V and VMware code does. It was a complete goof on my part (Sashiko also pointed out the oddity[*]). I fully intended to log a message and provide equivalent Hyper-V/VMware behavior, and totally spaced it. [*] https://lore.kernel.org/all/20260701194621.4BD691F000E9@smtp.kernel.org > I don't know that the message is all that useful, though I do remember one > case where I was debugging some clock/timer issue when I looked at it.