From mboxrd@z Thu Jan 1 00:00:00 1970 From: paulmck@linux.vnet.ibm.com (Paul E. McKenney) Date: Tue, 12 May 2015 14:50:05 -0700 Subject: [PATCH tip/core/rcu 7/9] arm64: Use common outgoing-CPU-notification code In-Reply-To: <1431467407-1223-1-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150512214945.GA813@linux.vnet.ibm.com> <1431467407-1223-1-git-send-email-paulmck@linux.vnet.ibm.com> Message-ID: <1431467407-1223-7-git-send-email-paulmck@linux.vnet.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: "Paul E. McKenney" This commit removes the open-coded CPU-offline notification with new common code. In particular, this change avoids calling scheduler code using RCU from an offline CPU that RCU is ignoring. This is a minimal change. A more intrusive change might invoke the cpu_check_up_prepare() and cpu_set_state_online() functions at CPU-online time, which would allow onlining throw an error if the CPU did not go offline properly. Signed-off-by: Paul E. McKenney Cc: linux-arm-kernel at lists.infradead.org Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/kernel/smp.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 2cb008177252..a899c1beff54 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -253,15 +253,13 @@ static int op_cpu_kill(unsigned int cpu) return cpu_ops[cpu]->cpu_kill(cpu); } -static DECLARE_COMPLETION(cpu_died); - /* * called on the thread which is asking for a CPU to be shutdown - * waits until shutdown has completed, or it is timed out. */ void __cpu_die(unsigned int cpu) { - if (!wait_for_completion_timeout(&cpu_died, msecs_to_jiffies(5000))) { + if (!cpu_wait_death(cpu, 5)) { pr_crit("CPU%u: cpu didn't die\n", cpu); return; } @@ -294,7 +292,7 @@ void cpu_die(void) local_irq_disable(); /* Tell __cpu_die() that this CPU is now safe to dispose of */ - complete(&cpu_died); + (void)cpu_report_death(); /* * Actually shutdown the CPU. This must never fail. The specific hotplug -- 1.8.1.5