From nobody Tue Feb 10 07:21:29 2026 Received: from mta-64-226.siemens.flowmailer.net (mta-64-226.siemens.flowmailer.net [185.136.64.226]) (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 C9B0915531A for ; Mon, 5 Aug 2024 12:41:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.64.226 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722861718; cv=none; b=enXqKBxzgklsGBZ1YlvMICCG7PSBymPML8/1FUZ/S6I9Ay9YT6b12WInBi+9GDR18KrMHtg734G/xqYPkMUpyCyJ3BasXUbj301AQR9rb2B1oDIWSSx/LTvetxae6thPzLijhywl17UoGuw4iTG/jfO9wTX2R16WeyALS1NiVaI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722861718; c=relaxed/simple; bh=3A6rVcuW0m0078khO1mNI86Z9b7w2oQ3ht6yUDw5gfc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=XqX/he/dXxgmiube7dgaiC8eEWHS4yDS7mtHgyAoS5PwTX0grRiLUkF/6dOv1YeAYGMAt+yC/owhxl1S04CcIdLVHSkKBOWHTz6JHjbbr64khmKUrL32DtQWfouNfWUjgokE7Misv38Jma0NPManbpdnlffc9TA520/Lwm0WCJI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b=S9YqwyOF; arc=none smtp.client-ip=185.136.64.226 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b="S9YqwyOF" Received: by mta-64-226.siemens.flowmailer.net with ESMTPSA id 20240805124147f472750eb3c525785e for ; Mon, 05 Aug 2024 14:41:48 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=felix.moessbauer@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc:References:In-Reply-To; bh=z1LmfkSa79b3Ou+9g4Zco79UrjCLf4Sb2US5vjHH17Q=; b=S9YqwyOF76pn6ZoLSTpfiZGZNgK+ngZt8pMMBzuPpC2BMtP/Pjn383PAfbfVV017vsXUio P21Gzy+W9eku0WGncrJRauTDz58cgwSCTYP/OLYGQXCCwlpMHAEcRora4i/zy92TDn3C4H9K 1TWVsm4trgmaa8xfPQJD82VaSCsKITrqyOhjx27K6Tt9osQjRXZRuawSVtjuYx7/GRkqLi2Z /2k9SlhoTw2pOMZbedbqVTn5KQZbyT4+EG3NvAqSutCvavKv0KZjkmixg1hD5u2v13gL6iy9 WLWCOAFGTHhIWXc9LOZAUE48y8kH3f5YviICG/Qzh5UGsm8qoswa1ILQ==; From: Felix Moessbauer To: linux-kernel@vger.kernel.org Cc: Thomas Gleixner , Frederic Weisbecker , Anna-Maria Behnsen , jan.kiszka@siemens.com, Felix Moessbauer Subject: [PATCH 1/2] hrtimer: Document, that PI boosted tasks have no timer slack Date: Mon, 5 Aug 2024 14:41:15 +0200 Message-Id: <20240805124116.21394-2-felix.moessbauer@siemens.com> In-Reply-To: <20240805124116.21394-1-felix.moessbauer@siemens.com> References: <20240805124116.21394-1-felix.moessbauer@siemens.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-1321639:519-21489:flowmailer Content-Type: text/plain; charset="utf-8" The documentation of schedule_hrtimeout_range already states, that RT and DL tasks do not have a timer slack. However, no information about PI boosted tasks is given. The current implementation consistently ignores the timer slack also for PI boosted tasks (all tasks with a rt priority at time of programming the timer). This patch improves the documentation by stating that the timer slack is also ignored for PI boosted tasks. It does not include any functional change. Signed-off-by: Felix Moessbauer --- kernel/time/hrtimer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index b8ee320208d4..2b1469f61d9c 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -2311,7 +2311,7 @@ EXPORT_SYMBOL_GPL(schedule_hrtimeout_range_clock); * * The @delta argument gives the kernel the freedom to schedule the * actual wakeup to a time that is both power and performance friendly - * for regular (non RT/DL) tasks. + * for regular (non RT/DL or PI boosted) tasks. * The kernel give the normal best effort behavior for "@expires+@delta", * but may decide to fire the timer earlier, but no earlier than @expires. * --=20 2.39.2