From patchwork Thu May 30 13:45:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frederic Weisbecker X-Patchwork-Id: 13680439 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 AEC6D17622C; Thu, 30 May 2024 13:46:24 +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=1717076784; cv=none; b=eQV0YANO1pGViPQksBISR5qFjAOhp+Aop6lfIyXBOC02nz5/U2QQYpeCtWppwawiaREUTPuQoEks6Fp++66l2/GHyaRcHdwWlNDkI33lm4citlTnrGLtLq07Eknv0HagLJjfPfWFRaIDj/rqlcQKkLCboLBc+4aTJ8N9Em7+OuA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717076784; c=relaxed/simple; bh=vKDdPpz7jOZDNyAElQztvVPztBWXtOQUT0AcGjdM2eY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a3b76bIeXIqg8Xr/L/6Nuo6RAg10fm7W/KmRaG5XRlsDF0HIc2D4Ka8FYt/XyYn6iknJBT1SXC5kpXmB6IysalMvks1wxUhjkThJN9x8g43HJf5tlcfMT5PArJWN5SqrNI+lhOmT9v1CsVM6WdRP62ORWbhWjZ/sargLJvVMYi8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GfNVBNeQ; 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="GfNVBNeQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AF37C4AF0B; Thu, 30 May 2024 13:46:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717076784; bh=vKDdPpz7jOZDNyAElQztvVPztBWXtOQUT0AcGjdM2eY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GfNVBNeQ6tnVwZRHuT2REsRYE0fdHbYNj22cKYEgC12bhc2aTVqeaNIR9suq/y9jN O52ToT8GMFWz+t4OzQBylLmWCgaUlq+fGXpSyhJ3k8n+p1rwdBgAL1JVIHyHhz+CGB IUKLMqM2T+/TWNvv5hlapVDgXtgAtK1qNCay8YSyruX0pfkD7qk91JubzpgXFvTBFx RC4gOBtpveGEpBcwGEiYbjqcFHAArzaD3Mvmj/kJn7AI+Y1D2ovRE30zVX2p/IfKNQ kUm1vHm/+YI2eNRBIeZQEk398w2QzsYAnMgSbA+u9pUE8CbbGdhqcYssTJHOU+Ovi0 iUHDKJukf2a9Q== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , "Paul E . McKenney" , Uladzislau Rezki , Zqiang , rcu Subject: [PATCH 07/11] rcu/nocb: Remove halfway (de-)offloading handling from rcu_core()'s QS reporting Date: Thu, 30 May 2024 15:45:48 +0200 Message-ID: <20240530134552.5467-8-frederic@kernel.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240530134552.5467-1-frederic@kernel.org> References: <20240530134552.5467-1-frederic@kernel.org> Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 RCU core can't be running anymore while in the middle of (de-)offloading since this sort of transition now only applies to offline CPUs. The locked callback acceleration handling during the transition can therefore be removed. Signed-off-by: Frederic Weisbecker --- kernel/rcu/tree.c | 13 ------------- 1 file changed, 13 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e904c187c281..c502a38dc5f3 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2381,7 +2381,6 @@ rcu_report_qs_rdp(struct rcu_data *rdp) { unsigned long flags; unsigned long mask; - bool needacc = false; struct rcu_node *rnp; WARN_ON_ONCE(rdp->cpu != smp_processor_id()); @@ -2418,23 +2417,11 @@ rcu_report_qs_rdp(struct rcu_data *rdp) * to return true. So complain, but don't awaken. */ WARN_ON_ONCE(rcu_accelerate_cbs(rnp, rdp)); - } else if (!rcu_segcblist_completely_offloaded(&rdp->cblist)) { - /* - * ...but NOCB kthreads may miss or delay callbacks acceleration - * if in the middle of a (de-)offloading process. - */ - needacc = true; } rcu_disable_urgency_upon_qs(rdp); rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags); /* ^^^ Released rnp->lock */ - - if (needacc) { - rcu_nocb_lock_irqsave(rdp, flags); - rcu_accelerate_cbs_unlocked(rnp, rdp); - rcu_nocb_unlock_irqrestore(rdp, flags); - } } }