linux-kernel - [PATCH 4.4 333/342] x86/irq: Remove the cpumask allocation from send_cleanup

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Message-Id: <20160301234538.624534801@linuxfoundation.org>
Date:	Tue, 01 Mar 2016 23:55:36 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>, Thomas Gleixner <tglx@...utronix.de>,
	Borislav Petkov <bp@...en8.de>,
	Joe Lawrence <joe.lawrence@...atus.com>,
	Jiang Liu <jiang.liu@...ux.intel.com>,
	Jeremiah Mahler <jmmahler@...il.com>,
	<andy.shevchenko@...il.com>, Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 4.4 333/342] x86/irq: Remove the cpumask allocation from send_cleanup_vector()

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@...utronix.de>

commit 5da0c1217f05d2ccc9a8ed6e6e5c23a8a1d24dd6 upstream.

There is no need to allocate a new cpumask for sending the cleanup vector. The
old_domain mask is now protected by the vector_lock, so we can safely remove
the offline cpus from it and send the IPI with the resulting mask.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Tested-by: Borislav Petkov <bp@...en8.de>
Tested-by: Joe Lawrence <joe.lawrence@...atus.com>
Cc: Jiang Liu <jiang.liu@...ux.intel.com>
Cc: Jeremiah Mahler <jmmahler@...il.com>
Cc: andy.shevchenko@...il.com
Cc: Guenter Roeck <linux@...ck-us.net>
Link: http://lkml.kernel.org/r/20151231160106.967993932@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/x86/kernel/apic/vector.c |   16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -528,21 +528,11 @@ static struct irq_chip lapic_controller
 #ifdef CONFIG_SMP
 static void __send_cleanup_vector(struct apic_chip_data *data)
 {
-	cpumask_var_t cleanup_mask;
-
 	raw_spin_lock(&vector_lock);
+	cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
 	data->move_in_progress = 0;
-	if (unlikely(!alloc_cpumask_var(&cleanup_mask, GFP_ATOMIC))) {
-		unsigned int i;
-
-		for_each_cpu_and(i, data->old_domain, cpu_online_mask)
-			apic->send_IPI_mask(cpumask_of(i),
-					    IRQ_MOVE_CLEANUP_VECTOR);
-	} else {
-		cpumask_and(cleanup_mask, data->old_domain, cpu_online_mask);
-		apic->send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
-		free_cpumask_var(cleanup_mask);
-	}
+	if (!cpumask_empty(data->old_domain))
+		apic->send_IPI_mask(data->old_domain, IRQ_MOVE_CLEANUP_VECTOR);
 	raw_spin_unlock(&vector_lock);
 }