From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792768069; b=ZWXimMTWu9GXHfGg30n1t+Cj1CdCgzXjB9Tt+Ibt4D9FHxTqB7HO707ordiTcoFWvbXw 23fiXmKLyNhzvfFjB3nQ0D5PQIQHsNmApmUCqoLpPganIqqOdVe/2jzLbCIf3idhvAUCm Ew/tz/S+7ArXU3yu2o6vbZ92MZo3FpQZ8AdVeBMMYwEwfjmRRsa1/b0J4BOzQOyZnJW0O egLpvL5UPn5uDRRvkg8/HfkDMFLUeNfwXVqU6jIAJonh+L91zLCdfM59C+uB+usPKwnNU lWGxG5JsabQGOtn0GibkFr5AlvsllJkq44JaV5r3AeSB34oanxp4/9tbQBzlvZBwa7w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792768069; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition: Content-Transfer-Encoding:In-Reply-To; bh=UE9rWzGH8UjwxdIGL93K25DG+3x5w79Wpt62w3WJdRQ=; b=hSlXGe58xrKhUFMXMHRcHctzQsD6imhVKAA70nRXJAAkmnbnKRdI2rBsVQhQoiyn9S5d kKbvcf+qPcv/EDXVKKiGeTwATkwNAiDHT7FTg42/musoHs66enGOXRydsVaosunD3txad WvW8zacEFrcB9dgTD6BlyfIAf/bs2zpoTrLsdVCipwVLFH5Vx87HlH4xr5bZ4ey771Sc2 hsOUs8KQdgVFW6ToFZDIzjbaW6zGgsYgls57DlbvOwZJqEnntBXiaiJc8FA54v/gfE/V6 3f9MUbLpN9CDP7TbuR6PjvCtvGqVFs2ONJpq4yOjhrtYwtQHRDBv0DB12uFtEaAx79g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=cJEZ0WM5; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A549E606A31A for ; Fri, 23 Oct 2026 15:07:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=cJEZ0WM5 Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCA4F1F01828; Fri, 23 Oct 2026 15:07:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792768069; bh=UE9rWzGH8UjwxdIGL93K25DG+3x5w79Wpt62w3WJdRQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=cJEZ0WM5UpuzEn8HlxGN/fjhCns4vlPF7a3Uvyc0A3B25vvRTO3pNKE34u0xhdC91 Cx8M8BbpsuIphKX4lD6TRtIvwVlGX+x9qut/iqfHoZgsJoBs7yqI7x7KHYisUVwinj dqLuBV0k8hmCESlZtpjMEOJ1BcvjmURR0YZ4sbGaUaAwaT09b0rAI3YWLjWcIRIk6M ztWx5HLMlyjgHashYHA+vjfnYqBFio6J/9L8BKcahDECjF52S5qFyepkRKnsxFNiGl BMLKPENfoYzN5tosPdOcTcsZLzaoahmxVlXS/AhqTWpSeMFF187/oO5aeYMQQ7+XvY xPGd3XzZcimZQ== Date: Fri, 23 Oct 2026 17:07:46 +0200 From: Frederic Weisbecker To: Peng Wang Cc: Anna-Maria Behnsen , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , He Rongguang , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] tick/nohz: Reevaluate the tick for kicks flushed outside hardirq Message-ID: References: <20261023145101.8217-1-peng_wang@linux.alibaba.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20261023145101.8217-1-peng_wang@linux.alibaba.com> Le Fri, Oct 23, 2026 at 10:51:00PM +0800, Peng Wang a écrit : > The nohz full kick relies on IRQ exit to reevaluate the tick. However, > a remote kick can also be flushed from task context without an IRQ > exit guaranteed to follow. If a tick dependency is set or an earlier > timer is queued after the idle-exit reevaluation, the required tick > update can be delayed until another interrupt. > > Reevaluate the tick directly from the callback outside hardirq context. > Keep the existing IRQ-exit handling for hardirq callbacks. The offline > flush remains harmless because tick_sched_timer_dying() has already > cleared TS_FLAG_NOHZ. > > Fixes: 4b44a21dd640 ("irq_work, smp: Allow irq_work on call_single_queue") > Fixes: a5183862e76f ("tick/nohz: Conditionally restart tick on idle exit") > Suggested-by: Frederic Weisbecker > Co-developed-by: He Rongguang > Signed-off-by: He Rongguang > Signed-off-by: Peng Wang Reviewed-by: Frederic Weisbecker Thanks a lot! -- Frederic Weisbecker SUSE Labs