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Commit 08ed487c authored by Anna-Maria Gleixner's avatar Anna-Maria Gleixner Committed by Thomas Gleixner
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x86/oprofile/nmi: Remove superfluous smp_function_call_single() 



Since commit 1cf4f629 ("cpu/hotplug: Move online calls to
hotplugged cpu") the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are
always run on the hot plugged CPU, and as of commit 3b9d6da6
("cpu/hotplug: Fix rollback during error-out in __cpu_disable()")
the CPU_DOWN_FAILED notifier also runs on the hot plugged CPU.
This patch converts the SMP functional calls into direct calls.

smp_call_function_single() executes the function with interrupts
disabled. This calling convention is preserved.

Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Robert Richter <rric@kernel.org>
Cc: rt@linuxtronix.de
Cc: oprofile-list@lists.sf.net
Link: http://lkml.kernel.org/r/20161117183541.8588-19-bigeasy@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e5355cd6

arch/x86/oprofile/nmi_int.c

+12 −10
Original line number Diff line number Diff line
@@ -387,20 +387,24 @@ static void nmi_cpu_shutdown(void *dummy) 
	nmi_cpu_restore_registers(msrs);

}



static void nmi_cpu_up(void *dummy)

static void nmi_cpu_up(void)

{

	local_irq_disable();

	if (nmi_enabled)

		nmi_cpu_setup(dummy);

		nmi_cpu_setup(NULL);

	if (ctr_running)

		nmi_cpu_start(dummy);

		nmi_cpu_start(NULL);

	local_irq_enable();

}



static void nmi_cpu_down(void *dummy)

static void nmi_cpu_down(void)

{

	local_irq_disable();

	if (ctr_running)

		nmi_cpu_stop(dummy);

		nmi_cpu_stop(NULL);

	if (nmi_enabled)

		nmi_cpu_shutdown(dummy);

		nmi_cpu_shutdown(NULL);

	local_irq_enable();

}



static int nmi_create_files(struct dentry *root)
@@ -436,15 +440,13 @@ static int nmi_create_files(struct dentry *root) 
static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,

				 void *data)

{

	int cpu = (unsigned long)data;



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_DOWN_FAILED:

	case CPU_ONLINE:

		smp_call_function_single(cpu, nmi_cpu_up, NULL, 0);

		nmi_cpu_up();

		break;

	case CPU_DOWN_PREPARE:

		smp_call_function_single(cpu, nmi_cpu_down, NULL, 1);

		nmi_cpu_down();

		break;

	}

	return NOTIFY_DONE;