| From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Date: Wed, 24 May 2017 10:15:21 +0200 |
| Subject: [PATCH 10/32] KVM/PPC/Book3S HV: Use |
| cpuhp_setup_state_nocalls_cpuslocked() |
| |
| kvmppc_alloc_host_rm_ops() holds get_online_cpus() while invoking |
| cpuhp_setup_state_nocalls(). |
| |
| cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is |
| correct, but prevents the conversion of the hotplug locking to a percpu |
| rwsem. |
| |
| Use cpuhp_setup_state_nocalls_cpuslocked() to avoid the nested |
| call. Convert *_online_cpus() to the new interfaces while at it. |
| |
| Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
| Acked-by: Ingo Molnar <mingo@kernel.org> |
| Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> |
| Cc: kvm@vger.kernel.org |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| Cc: Steven Rostedt <rostedt@goodmis.org> |
| Cc: kvm-ppc@vger.kernel.org |
| Cc: Michael Ellerman <mpe@ellerman.id.au> |
| Cc: linuxppc-dev@lists.ozlabs.org |
| Cc: Alexander Graf <agraf@suse.com> |
| Link: http://lkml.kernel.org/r/20170524081547.809616236@linutronix.de |
| --- |
| arch/powerpc/kvm/book3s_hv.c | 14 +++++++------- |
| 1 file changed, 7 insertions(+), 7 deletions(-) |
| |
| --- a/arch/powerpc/kvm/book3s_hv.c |
| +++ b/arch/powerpc/kvm/book3s_hv.c |
| @@ -3359,7 +3359,7 @@ void kvmppc_alloc_host_rm_ops(void) |
| return; |
| } |
| |
| - get_online_cpus(); |
| + cpus_read_lock(); |
| |
| for (cpu = 0; cpu < nr_cpu_ids; cpu += threads_per_core) { |
| if (!cpu_online(cpu)) |
| @@ -3381,17 +3381,17 @@ void kvmppc_alloc_host_rm_ops(void) |
| l_ops = (unsigned long) ops; |
| |
| if (cmpxchg64((unsigned long *)&kvmppc_host_rm_ops_hv, 0, l_ops)) { |
| - put_online_cpus(); |
| + cpus_read_unlock(); |
| kfree(ops->rm_core); |
| kfree(ops); |
| return; |
| } |
| |
| - cpuhp_setup_state_nocalls(CPUHP_KVM_PPC_BOOK3S_PREPARE, |
| - "ppc/kvm_book3s:prepare", |
| - kvmppc_set_host_core, |
| - kvmppc_clear_host_core); |
| - put_online_cpus(); |
| + cpuhp_setup_state_nocalls_cpuslocked(CPUHP_KVM_PPC_BOOK3S_PREPARE, |
| + "ppc/kvm_book3s:prepare", |
| + kvmppc_set_host_core, |
| + kvmppc_clear_host_core); |
| + cpus_read_unlock(); |
| } |
| |
| void kvmppc_free_host_rm_ops(void) |