From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D54CC433DF for ; Wed, 24 Jun 2020 20:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 140DB20823 for ; Wed, 24 Jun 2020 20:13:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593029614; bh=qZiGFZJ7CbgHMHQDzAwiU/MwuJbSwOc7xfMxb2POM70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H3SfhaI4/EnujQgXw/RVCBckNhnzUB2hHB74kF308f09Xd014SJQXQdOQKsrIlrXh mrkBJKDRudH9K9E+n/VOO5pZvbjGgXgtEp0BSbnKoSiKm87UnG3odnXDCbtY0L/fYF kqldJkmJwfmzWC+3dkc85c1XYVXD1TuiQhHvfJwU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406543AbgFXUNc (ORCPT ); Wed, 24 Jun 2020 16:13:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:52478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406378AbgFXUM3 (ORCPT ); Wed, 24 Jun 2020 16:12:29 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BE6F32137B; Wed, 24 Jun 2020 20:12:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593029548; bh=qZiGFZJ7CbgHMHQDzAwiU/MwuJbSwOc7xfMxb2POM70=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XRtnN15DHCLVpUxcpepum/t4ehq5kOCp9+gqEP0sZDHsfH4Be6YMnZ+vsiYb8iPTU KOUm2MT0YRADhRVhluZ/fhAw3Uhk8RbrtQsMD8Qh7/0Vdc+Ji6GTK+AWX9b861Cjoi mFk4qYeY8pQG3FL1RRc0IvigdyFHMv7bjY5QfOBo= From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Uladzislau Rezki (Sony)" , "Paul E . McKenney" Subject: [PATCH tip/core/rcu 04/17] rcu/tree: Repeat the monitor if any free channel is busy Date: Wed, 24 Jun 2020 13:12:13 -0700 Message-Id: <20200624201226.21197-4-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200624201200.GA28901@paulmck-ThinkPad-P72> References: <20200624201200.GA28901@paulmck-ThinkPad-P72> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Uladzislau Rezki (Sony)" It is possible that one of the channels cannot be detached because its free channel is busy and previously queued data has not been processed yet. On the other hand, another channel can be successfully detached causing the monitor work to stop. Prevent that by rescheduling the monitor work if there are any channels in the pending state after a detach attempt. Fixes: 34c881745549e ("rcu: Support kfree_bulk() interface in kfree_rcu()") Acked-by: Joel Fernandes (Google) Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index dbdd509..31d3b2c 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3087,7 +3087,7 @@ static void kfree_rcu_work(struct work_struct *work) static inline bool queue_kfree_rcu_work(struct kfree_rcu_cpu *krcp) { struct kfree_rcu_cpu_work *krwp; - bool queued = false; + bool repeat = false; int i; lockdep_assert_held(&krcp->lock); @@ -3125,11 +3125,14 @@ static inline bool queue_kfree_rcu_work(struct kfree_rcu_cpu *krcp) * been detached following each other, one by one. */ queue_rcu_work(system_wq, &krwp->rcu_work); - queued = true; } + + /* Repeat if any "free" corresponding channel is still busy. */ + if (krcp->bhead || krcp->head) + repeat = true; } - return queued; + return !repeat; } static inline void kfree_rcu_drain_unlock(struct kfree_rcu_cpu *krcp, -- 2.9.5