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Subject[tip:smp/hotplug] x86/oprofile/nmi: Remove superfluous smp_function_call_single()
Commit-ID:  08ed487c819d285c3f6ceafd156094102acdfec2
Gitweb: http://git.kernel.org/tip/08ed487c819d285c3f6ceafd156094102acdfec2
Author: Anna-Maria Gleixner <anna-maria@linutronix.de>
AuthorDate: Thu, 17 Nov 2016 19:35:39 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 22 Nov 2016 23:34:42 +0100

x86/oprofile/nmi: Remove superfluous smp_function_call_single()

Since commit 1cf4f629d9d2 ("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 3b9d6da67e11
("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: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian 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: Thomas Gleixner <tglx@linutronix.de>

---
arch/x86/oprofile/nmi_int.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 28c0412..c39172c 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -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;
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