From mboxrd@z Thu Jan 1 00:00:00 1970 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 1382E1C2AF; Tue, 26 Mar 2024 17:18:43 +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=1711473524; cv=none; b=X4iT7aTpVlgiOIpMMC7GxGpaIKhOefAQYZyYEWbX4bbBPBSLSmn7OPlhbAhWx7YD1StRoLlvN7+G2m73EdOQrHY+VaklcWKkjJ2xRORzIWldUFemuRSLA2SuTr3KbZXzDE8RXOdGHvfz1yzFoY30ywFpOc48/mFucT7t5dfsm6s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711473524; c=relaxed/simple; bh=OELWXVXqN2pN+dBq4GD1HVskjaEZn6Buw4ZbYGID18o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ecXK5D599gnJxmHXxpHSGPzLz0ecBoONOt+ctHL9x8pnO354cp2GJlhw+DrsVqurAp4guw0rN1dIAZBcurZfJuKtreK0KtFUKLt4kmS9xp0F8yU+jb83Xom9WCWjF2KPnq6GbtJaBvYqs2n3LbN+/r1fNdBpZA4CSr8JXNU6V5c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iUEVgwaR; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iUEVgwaR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34370C433F1; Tue, 26 Mar 2024 17:18:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711473523; bh=OELWXVXqN2pN+dBq4GD1HVskjaEZn6Buw4ZbYGID18o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iUEVgwaRX6aZT96UVqp/fsF/1hcY/RgzUvzjtwC5cX1+hGXneR17p20DLXj0hIRXg v8K42vdYEcJFrPhrvT/0JqQW14LJn43VfImA/3ZCK2r4vGCxporMdRwsik+G0BL58Z iOQT+Od3cOvcfCS2sh8ciYDevDXN74aV/3iCSu8tcRcsFDg/Ixrxp+1EmpSVSnpgHb KCCYBndtAMg4d6OV6dJI2ZyxCyBW269zKSgNY0KEAAFDHerUHeB2/t9WuwNn3tcKeg 8GMeJdJj+41O5Y/16Za6KQ7TLfqj35YX2B1NwWkueaDev+Qp+FJ2dlOz9ZlGVHxLb/ Z2c32NPbyiKuw== Date: Tue, 26 Mar 2024 18:18:40 +0100 From: Frederic Weisbecker To: Anna-Maria Behnsen Cc: Boqun Feng , Florian Fainelli , Thomas Gleixner , "Russell King (Oracle)" , Joel Fernandes , Linus Torvalds , linux-kernel@vger.kernel.org, kernel-team@meta.com, paulmck@kernel.org, mingo@kernel.org, rcu@vger.kernel.org, neeraj.upadhyay@amd.com, urezki@gmail.com, qiang.zhang1211@gmail.com, bigeasy@linutronix.de, chenzhongjin@huawei.com, yangjihong1@huawei.com, rostedt@goodmis.org, Justin Chen Subject: Re: [PATCH] timer/migration: Remove buggy early return on deactivation [was Re: Unexplained long boot delays [Was Re: [GIT PULL] RCU changes for v6.9]] Message-ID: References: <87v85olez3.ffs@tglx> <87sf0sldbi.ffs@tglx> <87zfulrlnn.fsf@somnus> 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: <87zfulrlnn.fsf@somnus> Le Tue, Mar 26, 2024 at 05:41:00PM +0100, Anna-Maria Behnsen a écrit : > Frederic Weisbecker writes: > Now propagation goes on as GRP0:0 is completely idle. When executing > tmigr_update_events() in the next step of walking the hierarchy via > tmigr_inactive_up(), the arguments for tmigr_update_events() are set in > the following way: > > group = GRP1:0 > child = GRP0:0 > > Then at the begin of tmigr_update_events() the group event of child is > updated - so all ignored events are removed (T0i), and the > child->groupevt and child->next_expiry is updated with T1. This > reevaluated child->groupevt is then queued/updated in the GRP1:0 > timerqueue. > > So T1 will be handled! > > As there is no parent, the top level group event is updated (see goto > label "check_toplvl") and T1 will be still the first event. Bah! Good point, I got confused there... > > > Fix those issues with removing the buggy related early return. Ignored > > child events must not prevent from evaluating the other events within > > the same group. > > I would prefere to keep this early return but skip it, when there is > !group->parent (only a single level in hierarchy). > > Then it would prevent taking the group lock and making some random > event updates which are done nevertheless on the next iteration of the > hierarchy walk. Ok sounds like a good plan! Thanks. > > Thanks, > > Anna-Maria >