From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 6574C13F435 for ; Tue, 12 Nov 2024 14:48:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731422926; cv=none; b=IU+3Wrb55WSpRz8CIJAyyhTvBznV+trsHsZSZ5qZyqi1zoCidLGJoiiC4mBUIeI4g4tbFGakrVPV/I0D1L+rJp7sKvElJ2lt2SDg5eXYWqtRnM+Fas62OjWqeSRwAng4xg+2h5CWkdCmiM3KPSK8VuPq216qsKKNYLfTbmiF+Aw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731422926; c=relaxed/simple; bh=D61eWjOrFwpgEFmkwTFdnMMEWAwxYM8vo6p7qTrJLoo=; h=From:To:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=YZgDUrdD1whsSgr9ECkQLkYaMec4oIdNENcO60zwxuQDOBpFAvmwq9d2GoXTJ2AzFIvWRMSf4B8TKxNtKgfYM4dUVe76JiCalUi+nHbP/fQ251sB/vYuIJkmYEninY2Uj+CGwx6KK1+qFwCwDYRM9kDBO1Z8p0OWGOIOPmuVYlw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=F1B6DnyH; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=sKKYrTPv; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="F1B6DnyH"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="sKKYrTPv" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1731422919; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=pwdFJEsHTVikOnAMWlThCtaM9ig0AlTkkrxPLwh79S8=; b=F1B6DnyHBcOeFoSpLz6a11tktazX2qCPB4z7i0+Js4oPjybyj07gKBlXK6fMjWGDHyPBap 88T3caRR34Ps3P0kF80WU0qKE/+Wot8VaM+//yRibCBp7oBrJwOdeeP5EVlZqpgKkL58Sj fAHbO0UYMiEvkfnBqFv5v8MjQrozGTJoF6Ntvyd5Xi4QH3rl2JCs0kdnb7qHX4bfOFrEnE v3EVZrlgbbc9R3wqysXkQcfOCWWhUF39PNiHjhtJictJHg7feRMPUV4dcHWEqFQ3Iqp8CL voBVH/u47QZnbG0HSDfDZD1e/tNSDOElLOfhAYgoGi/kGcJaHl8NZRhBKzIaxg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1731422919; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=pwdFJEsHTVikOnAMWlThCtaM9ig0AlTkkrxPLwh79S8=; b=sKKYrTPvI5stYDSsj/LgJmZNDhL+U3P2w25SVv0kCXkpnoKJeK8Bfs+QbQuc7Epudv/DJi 4D6fc9n2r2e4jFAQ== To: Joel Fernandes , linux-kernel@vger.kernel.org, Anna-Maria Behnsen , Frederic Weisbecker , Ingo Molnar Subject: Re: [RFC 3/3] tick-sched: Replace jiffie readout with idle_entrytime In-Reply-To: <20241110225545.GA1579217@google.com> References: <20241108174839.1016424-1-joel@joelfernandes.org> <20241108174839.1016424-4-joel@joelfernandes.org> <20241110225545.GA1579217@google.com> Date: Tue, 12 Nov 2024 15:48:43 +0100 Message-ID: <87y11omrsk.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 Sun, Nov 10 2024 at 22:55, Joel Fernandes wrote: > > + /* > + * There is some time that passes between when clocksource starts and the > + * first time tick device is setup. Offset basejiff by that. > + */ > + basejiff -= DIV_ROUND_DOWN_ULL(tick_first_period, TICK_NSEC); We clearly need yet another division here. Especially as that division results in the exactly same value every time.