From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 50/51] net/core/flow.c: Fix CPU hotplug callback registration Date: Thu, 06 Feb 2014 21:19:50 -0800 (PST) Message-ID: <20140206.211950.143290861607860665.davem@davemloft.net> References: <20140205220251.19080.92336.stgit@srivatsabhat.in.ibm.com> <20140205221345.19080.20784.stgit@srivatsabhat.in.ibm.com> <20140206.203921.888218847049631688.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: paulus@samba.org, oleg@redhat.com, rusty@rustcorp.com.au, peterz@infradead.org, tglx@linutronix.de, akpm@linux-foundation.org, mingo@kernel.org, paulmck@linux.vnet.ibm.com, tj@kernel.org, walken@google.com, ego@linux.vnet.ibm.com, linux@arm.linux.org.uk, linux-kernel@vger.kernel.org, roy.qing.li@gmail.com, sasha.levin@oracle.com, cmetcalf@tilera.com, netdev@vger.kernel.org To: srivatsa.bhat@linux.vnet.ibm.com Return-path: In-Reply-To: <20140206.203921.888218847049631688.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: David Miller Date: Thu, 06 Feb 2014 20:39:21 -0800 (PST) > From: "Srivatsa S. Bhat" > Date: Thu, 06 Feb 2014 03:43:46 +0530 > >> Subsystems that want to register CPU hotplug callbacks, as well as perform >> initialization for the CPUs that are already online, often do it as shown >> below: > ... >> This is wrong, since it is prone to ABBA deadlocks involving the >> cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently >> with CPU hotplug operations). >> >> Instead, the correct and race-free way of performing the callback >> registration is: > ... >> Fix the code in net/core/flow.c by using this latter form of callback >> registration. >> >> Cc: "David S. Miller" >> Cc: Li RongQing >> Cc: Sasha Levin >> Cc: Andrew Morton >> Cc: Chris Metcalf >> Cc: netdev@vger.kernel.org >> Signed-off-by: Srivatsa S. Bhat > > Applied. I just realized that this has a dependency not in the 'net' tree, so I reverted and assume you will merge this with the patch that provides the necessary interface(s). Signed-off-by: David S. Miller