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 A36571E87B; Fri, 21 Feb 2025 15:31:10 +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=1740151870; cv=none; b=HXaa3sp5sMy+y565Y3h/eQUNNgjI31rF+2CnrPGm/RLXU19+KEyocnBOWZskkMXRI9umpJue+w+b1aEAade6Mp+Qyjqri/HWPPplKlvwLSGGcdOhm7a8pW+8iTpQvcnN0r3uSuAY6KklkVCTnKvyxQ6gt988elPZmLYCpDtWgGo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740151870; c=relaxed/simple; bh=DAAOHAFUSIYiuwahp3IQS9xds/bKBMPw8aEZIGAnf/M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Cbhf4zprjBKMSXnOX6juRAMlEDy/CKqPBelcSFxKd4KEfTI9lnNRP3lvoBNp6mvL59jUDe0rP6XGlsIImQr+ATPwMyiNFcIFiLtcdszqub7mq8+7FAnOayQt3kuOzxfrLRyOaMGQoIAFYu6iAXtmSX+iXvbf4if6vBCfVK/6Vq8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XpGMqtF5; 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="XpGMqtF5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2093C4CED6; Fri, 21 Feb 2025 15:31:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740151870; bh=DAAOHAFUSIYiuwahp3IQS9xds/bKBMPw8aEZIGAnf/M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XpGMqtF5iMuNnuD2Fzs+ukabyq6pfy1i5HLQN14mOO8hEGGq7fzK65N2uwcveYOxr 27N9r+DxLUm6RX8gxYdN1O0IR5s38cFD1+V70QDEZJNb9UHnYbjSlGcaaWbvc5L/s5 dgOYbyKm4uGYcfGz5ShHfUSnRnSzzWihz5E4paROu9cCzvcsC2TEQ8tE67vmw/dya/ wo5aqzmkVrN2yvJ1ACWfSGX/E5fjb8L+AG1be9RFUyPaPBEDe0y4o91F0QYVFVgneH jPapLBrHE2pGQDTFhijvAW37Gd3QuOyyFeFpWKTcNksT3CiG/O8WQ312e5PlX9hINw RcEFFnltBZ68g== Date: Fri, 21 Feb 2025 16:31:07 +0100 From: Frederic Weisbecker To: "Paul E. McKenney" Cc: LKML , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , Uladzislau Rezki , Zqiang , rcu Subject: Re: [PATCH 3/3] rcu/exp: Remove needless CPU up quiescent state report Message-ID: References: <20250213232559.34163-1-frederic@kernel.org> <20250213232559.34163-4-frederic@kernel.org> <610596cf-9836-473f-bcdc-15c69b7e0cd4@paulmck-laptop> <966fe653-7dbf-40b6-8b6e-c9bcf7b34335@paulmck-laptop> 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: <966fe653-7dbf-40b6-8b6e-c9bcf7b34335@paulmck-laptop> Le Wed, Feb 19, 2025 at 07:55:05AM -0800, Paul E. McKenney a écrit : > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > index 86935fe00397..40d6090a33f5 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -4347,6 +4347,12 @@ void rcutree_report_cpu_dead(void) > > > * may introduce a new READ-side while it is actually off the QS masks. > > > */ > > > lockdep_assert_irqs_disabled(); > > > + /* > > > + * CPUHP_AP_SMPCFD_DYING was the last call for rcu_exp_handler() execution. > > > + * The requested QS must have been reported on the last context switch > > > + * from stop machine to idle. > > > + */ > > > + WARN_ON_ONCE(rdp->cpu_no_qs.b.exp); > > > // Do any dangling deferred wakeups. > > > do_nocb_deferred_wakeup(rdp); > > > > I fired off a 30-minute run of 100*TREE03 with this change also. > > And no failures! Ok I'm adding that one on my queue. > > Thanx, Paul > > > > > 3. Your ideas here! ;-) > > > > > > :-) > > > > Thanx, Paul