From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: kvm-ppc@xxxxxxxxxxxxxxx
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: Alexander Graf <agraf@xxxxxxxx>
---
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
@@ -3317,7 +3317,7 @@ 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))
@@ -3339,17 +3339,17 @@ 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)
--
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