| Date | Fri, 26 May 2017 01:40:02 -0700 | From | tip-bot for Sebastian Andrzej Siewior <> | Subject | [tip:smp/hotplug] powerpc/powernv: Use stop_machine_cpuslocked() |
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Commit-ID: f9a69931c3959940538884d5962b770c3db75df5 Gitweb: http://git.kernel.org/tip/f9a69931c3959940538884d5962b770c3db75df5 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> AuthorDate: Wed, 24 May 2017 10:15:27 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 26 May 2017 10:10:41 +0200
powerpc/powernv: Use stop_machine_cpuslocked()
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_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: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170524081548.331016542@linutronix.de
--- arch/powerpc/platforms/powernv/subcore.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c index 0babef1..e6230f10 100644 --- a/arch/powerpc/platforms/powernv/subcore.c +++ b/arch/powerpc/platforms/powernv/subcore.c @@ -348,7 +348,7 @@ static int set_subcores_per_core(int new_mode) state->master = 0; } - get_online_cpus(); + cpus_read_lock(); /* This cpu will update the globals before exiting stop machine */ this_cpu_ptr(&split_state)->master = 1; @@ -356,9 +356,10 @@ static int set_subcores_per_core(int new_mode) /* Ensure state is consistent before we call the other cpus */ mb(); - stop_machine(cpu_update_split_mode, &new_mode, cpu_online_mask); + stop_machine_cpuslocked(cpu_update_split_mode, &new_mode, + cpu_online_mask); - put_online_cpus(); + cpus_read_unlock(); return 0; }
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