[patch V2 07/24] KVM/PPC/Book3S HV: Use cpuhp_setup_state_nocalls_cpuslocked()

Thomas Gleixner tglx at linutronix.de
Wed Apr 19 03:04:49 AEST 2017


From: Sebastian Andrzej Siewior <bigeasy at linutronix.de>

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.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Cc: Alexander Graf <agraf at suse.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: kvm at vger.kernel.org
Cc: kvm-ppc at vger.kernel.org
Cc: linuxppc-dev at lists.ozlabs.org

---
 arch/powerpc/kvm/book3s_hv.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3336,10 +3336,10 @@ void kvmppc_alloc_host_rm_ops(void)
 		return;
 	}
 
-	cpuhp_setup_state_nocalls(CPUHP_KVM_PPC_BOOK3S_PREPARE,
-				  "ppc/kvm_book3s:prepare",
-				  kvmppc_set_host_core,
-				  kvmppc_clear_host_core);
+	cpuhp_setup_state_nocalls_cpuslocked(CPUHP_KVM_PPC_BOOK3S_PREPARE,
+					     "ppc/kvm_book3s:prepare",
+					     kvmppc_set_host_core,
+					     kvmppc_clear_host_core);
 	put_online_cpus();
 }
 




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