From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758001AbcBXFJh (ORCPT ); Wed, 24 Feb 2016 00:09:37 -0500 Received: from e19.ny.us.ibm.com ([129.33.205.209]:45419 "EHLO e19.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757855AbcBXFHp (ORCPT ); Wed, 24 Feb 2016 00:07:45 -0500 X-IBM-Helo: d01dlp02.pok.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: 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, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 12/14] documentation: Document illegality of call_rcu() from offline CPUs Date: Tue, 23 Feb 2016 21:00:45 -0800 Message-Id: <1456290047-16654-12-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 2.5.2 In-Reply-To: <20160224050021.GA14616@linux.vnet.ibm.com> References: <20160224050021.GA14616@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16022405-0057-0000-0000-00000383080B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is already a blanket statement about no member of RCU's API being legal from an offline CPU, but add an explicit note where it states that it is illegal to invoke call_rcu() from an NMI handler. Signed-off-by: Paul E. McKenney --- Documentation/RCU/Design/Requirements/Requirements.html | 3 ++- Documentation/RCU/Design/Requirements/Requirements.htmlx | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/Documentation/RCU/Design/Requirements/Requirements.html b/Documentation/RCU/Design/Requirements/Requirements.html index 2a56031bfdd4..01e12b86e81f 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.html +++ b/Documentation/RCU/Design/Requirements/Requirements.html @@ -1354,7 +1354,8 @@ situations where neither synchronize_rcu() nor synchronize_rcu_expedited() would be legal, including within preempt-disable code, local_bh_disable() code, interrupt-disable code, and interrupt handlers. -However, even call_rcu() is illegal within NMI handlers. +However, even call_rcu() is illegal within NMI handlers +and from offline CPUs. The callback function (remove_gp_cb() in this case) will be executed within softirq (software interrupt) environment within the Linux kernel, diff --git a/Documentation/RCU/Design/Requirements/Requirements.htmlx b/Documentation/RCU/Design/Requirements/Requirements.htmlx index 98da30ca84c4..3355f1f9384c 100644 --- a/Documentation/RCU/Design/Requirements/Requirements.htmlx +++ b/Documentation/RCU/Design/Requirements/Requirements.htmlx @@ -1513,7 +1513,8 @@ situations where neither synchronize_rcu() nor synchronize_rcu_expedited() would be legal, including within preempt-disable code, local_bh_disable() code, interrupt-disable code, and interrupt handlers. -However, even call_rcu() is illegal within NMI handlers. +However, even call_rcu() is illegal within NMI handlers +and from offline CPUs. The callback function (remove_gp_cb() in this case) will be executed within softirq (software interrupt) environment within the Linux kernel, -- 2.5.2