From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yong Zhang Date: Tue, 29 May 2012 07:16:02 +0000 Subject: [RFC PATCH 07/10] ia64: smp: remove call to ipi_call_lock_irq()/ipi_call_unlock_irq() Message-Id: <1338275765-3217-8-git-send-email-yong.zhang0@gmail.com> List-Id: References: <1338275765-3217-1-git-send-email-yong.zhang0@gmail.com> In-Reply-To: <1338275765-3217-1-git-send-email-yong.zhang0@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org Cc: ralf@linux-mips.org, sshtylyov@mvista.com, david.daney@cavium.com, nikunj@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, axboe@kernel.dk, mingo@kernel.org, tglx@linutronix.de, peterz@infradead.org, akpm@linux-foundation.org, srivatsa.bhat@linux.vnet.ibm.com, Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org From: Yong Zhang 1) call_function.lock used in smp_call_function_many() is just to protect call_function.queue and &data->refs, cpu_online_mask is outside of the lock. And it's not necessary to protect cpu_online_mask, because data->cpumask is pre-calculate and even if a cpu is brougt up when calling arch_send_call_function_ipi_mask(), it's harmless because validation test in generic_smp_call_function_interrupt() will take care of it. 2) For cpu down issue, stop_machine() will guarantee that no concurrent smp_call_fuction() is processing. Signed-off-by: Yong Zhang Cc: Tony Luck Cc: Fenghua Yu Cc: linux-ia64@vger.kernel.org --- arch/ia64/kernel/smpboot.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 1113b8a..963d2db 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -382,7 +382,6 @@ smp_callin (void) set_numa_node(cpu_to_node_map[cpuid]); set_numa_mem(local_memory_node(cpu_to_node_map[cpuid])); - ipi_call_lock_irq(); spin_lock(&vector_lock); /* Setup the per cpu irq handling data structures */ __setup_vector_irq(cpuid); @@ -390,7 +389,6 @@ smp_callin (void) set_cpu_online(cpuid, true); per_cpu(cpu_state, cpuid) = CPU_ONLINE; spin_unlock(&vector_lock); - ipi_call_unlock_irq(); smp_setup_percpu_timer(); -- 1.7.5.4