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[2604:1380:45e3:2400::1]) by mx.google.com with ESMTPS id 6-20020a170902e9c600b001d9cf98cfc0si368479plk.565.2024.02.12.07.24.00 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Feb 2024 07:24:01 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-61887-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=g3ajAkcW; arc=pass (i=1 dkim=pass dkdomain=kernel.org); spf=pass (google.com: domain of linux-kernel+bounces-61887-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-61887-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 695DB283DA0 for ; Mon, 12 Feb 2024 15:24:00 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9D22C3C480; Mon, 12 Feb 2024 15:23:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="g3ajAkcW" 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 C930B3C087 for ; Mon, 12 Feb 2024 15:23:53 +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=1707751433; cv=none; b=cGNAAOk/VMp31FsQgxHC3DuavaTuXOuOM5TGfNQ1bXD7wG0Ao6TVlNLS3AKl0urVxcY9dSpTL6Q7ZspkryzGgpJ4gHkWDtr0ZBEB/5Ef+JtAa8mQt67oM1G6Ti20FVu1IuVzabI1ZBeB2ITWNkpH3Ur6qpnEzykQ3UJAHuZBkDQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707751433; c=relaxed/simple; bh=cYaR6ewOWivZZlu2DDOh0DduYyQR/eNhIL9vDyNReew=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NLLU2pg7s3RK8PitLEjBI6uqY6KIe2jq9PtM0I5+pBMHbt0CzYurxjIh+N4vl2m1d42s2uOgqhvxawZaDE3wwdSK5KlKMQtpTo7YCuTIRqOY6zOPEq2SQfsHz9Nig3GvlvoV2B/NN/w0l1/LPJ3SRUua/NpXu7SJYsb1UPHyrrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=g3ajAkcW; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FE9DC433C7; Mon, 12 Feb 2024 15:23:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707751433; bh=cYaR6ewOWivZZlu2DDOh0DduYyQR/eNhIL9vDyNReew=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=g3ajAkcW8V+khACIZ14JHJM9bYHDzSX1C26WVvQZx6z5ieTGCXrzXY7a4GcAXIv+1 Ijl5F4vGhkhQsUwd5bmJxeDUYySST0LmAo2molV/d57vXkAoqM9slOkcoOoNXojjPl rCLc1xQfN6NskdsrC9EGTUZy6MXJLyTr0qUeejv/tTwT4GrDABzagmnIwq0AAwUHbQ YgOjegQ6RuaixSJcWz6JcFtWOb3CGPl4scPsXXdGOThvFBnGcVAmeJuICpyr7KyUiL qjk1YyEODxAcG9O4qQe14njzvfqSWj4zDC27EHoAJPTOXemgAH6QzGjC79INyLMnzq Q/+pfp8Rfuz2A== Date: Mon, 12 Feb 2024 16:23:48 +0100 From: Frederic Weisbecker To: Costa Shulyupin Cc: Waiman Long , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] hrtimer: select housekeeping CPU during migration Message-ID: References: <20240211135213.2518068-1-costa.shul@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240211135213.2518068-1-costa.shul@redhat.com> Le Sun, Feb 11, 2024 at 03:52:13PM +0200, Costa Shulyupin a ?crit : > because during CPU deactivation a timer can migrate > to isolated CPU and break CPU isolation. > > For reference see function get_nohz_timer_target, > which selects CPU for new timers from housekeeping_cpumask(HK_TYPE_TIMER) > > Inspired by Waiman Long > > Signed-off-by: Costa Shulyupin Reviewed-by: Frederic Weisbecker