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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sebastian Siewior <bigeasy@linutronix.de>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	linuxppc-dev@lists.ozlabs.org
Subject: [patch 13/20] powerpc/powernv: Use stop_machine_locked()
Date: Sat, 15 Apr 2017 19:01:20 +0200	[thread overview]
Message-ID: <20170415171652.331526644@linutronix.de> (raw)
In-Reply-To: 20170415170107.643253702@linutronix.de

set_subcores_per_core() holds get_online_cpus() while invoking stop_machine().

stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use stop_machine_locked() to avoid the nested call.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org

---
 arch/powerpc/platforms/powernv/subcore.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/platforms/powernv/subcore.c
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -356,7 +356,7 @@ static int set_subcores_per_core(int new
 	/* Ensure state is consistent before we call the other cpus */
 	mb();
 
-	stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask);
+	stop_machine_locked(cpu_update_split_mode, &new_mode, cpu_online_mask);
 
 	put_online_cpus();
 

      parent reply	other threads:[~2017-04-15 17:31 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20170415170107.643253702@linutronix.de>
2017-04-15 17:01 ` [patch 07/20] KVM/PPC/Book3S HV: Use cpuhp_setup_state_nocalls_locked() Thomas Gleixner
2017-04-15 17:01 ` Thomas Gleixner [this message]

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