From bc6833009583bd5b096ef7aa2bb006854a5a2dce Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Tue, 29 May 2012 16:27:33 +0800 Subject: [PATCH] SPARC: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq() ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock protects only the call_function data structure itself, but it's completely unrelated to cpu_online_mask. The mask to which the IPIs are sent is calculated before call_function.lock is taken in smp_call_function_many(), so the locking around set_cpu_online() is pointless and can be removed. Delay irq enable to after set_cpu_online(). [ tglx: Massaged changelog ] Signed-off-by: Yong Zhang Cc: ralf@linux-mips.org Cc: sshtylyov@mvista.com Cc: david.daney@cavium.com Cc: nikunj@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: axboe@kernel.dk Cc: peterz@infradead.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/20120529082732.GA4250@zhy Acked-by: "David S. Miller" Acked-by: Srivatsa S. Bhat Acked-by: Peter Zijlstra Signed-off-by: Thomas Gleixner --- arch/sparc/kernel/smp_64.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index f591598d92f6..781bcb10b8bd 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -103,8 +103,6 @@ void __cpuinit smp_callin(void) if (cheetah_pcache_forced_on) cheetah_enable_pcache(); - local_irq_enable(); - callin_flag = 1; __asm__ __volatile__("membar #Sync\n\t" "flush %%g6" : : : "memory"); @@ -124,9 +122,8 @@ void __cpuinit smp_callin(void) while (!cpumask_test_cpu(cpuid, &smp_commenced_mask)) rmb(); - ipi_call_lock_irq(); set_cpu_online(cpuid, true); - ipi_call_unlock_irq(); + local_irq_enable(); /* idle thread is expected to have preempt disabled */ preempt_disable(); @@ -1308,9 +1305,7 @@ int __cpu_disable(void) mdelay(1); local_irq_disable(); - ipi_call_lock(); set_cpu_online(cpu, false); - ipi_call_unlock(); cpu_map_rebuild(); -- 2.34.1