From: Sumit.Saxena@avagotech.com <Sumit.Saxena@avagotech.com>
Date: Fri, 12 Sep 2014 13:27:48 +0000 (+0530)
Subject: megaraid_sas : Add module parameter to disable IRQ-CPU affinity hint
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=ac95136ad40fc72c4842fee1ef002390ad96bfa0;p=deliverable%2Flinux.git

megaraid_sas : Add module parameter to disable IRQ-CPU affinity hint

Resending the patch. Addressed the review comments from Tomas Henzl.

For certain deployment, we may need to disable irq cpu affinity hint.
This module parameter provides option for use to disable irq cpu affinity hint
and allow irqbalancer to handle the rest.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index bc79a0568acf..4c4c266e2388 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -89,6 +89,10 @@ module_param(resetwaittime, int, S_IRUGO);
 MODULE_PARM_DESC(resetwaittime, "Wait time in seconds after I/O timeout "
 		 "before resetting adapter. Default: 180");
 
+int smp_affinity_enable = 1;
+module_param(smp_affinity_enable, int, S_IRUGO);
+MODULE_PARM_DESC(smp_affinity_enable, "SMP affinity feature enable/disbale Default: enable(1)");
+
 MODULE_LICENSE("GPL");
 MODULE_VERSION(MEGASAS_VERSION);
 MODULE_AUTHOR("megaraidlinux@lsi.com");
@@ -5162,8 +5166,9 @@ retry_irq_register:
 				printk(KERN_DEBUG "megasas: Failed to "
 				       "register IRQ for vector %d.\n", i);
 				for (j = 0; j < i; j++) {
-					irq_set_affinity_hint(
-						instance->msixentry[j].vector, NULL);
+					if (smp_affinity_enable)
+						irq_set_affinity_hint(
+							instance->msixentry[j].vector, NULL);
 					free_irq(
 						instance->msixentry[j].vector,
 						&instance->irq_context[j]);
@@ -5172,11 +5177,14 @@ retry_irq_register:
 				instance->msix_vectors = 0;
 				goto retry_irq_register;
 			}
-			if (irq_set_affinity_hint(instance->msixentry[i].vector,
-				get_cpu_mask(cpu)))
-				dev_err(&instance->pdev->dev, "Error setting"
-					"affinity hint for cpu %d\n", cpu);
-			cpu = cpumask_next(cpu, cpu_online_mask);
+			if (smp_affinity_enable) {
+				if (irq_set_affinity_hint(instance->msixentry[i].vector,
+					get_cpu_mask(cpu)))
+					dev_err(&instance->pdev->dev,
+						"Error setting affinity hint "
+						"for cpu %d\n", cpu);
+				cpu = cpumask_next(cpu, cpu_online_mask);
+			}
 		}
 	} else {
 		instance->irq_context[0].instance = instance;
@@ -5235,8 +5243,9 @@ retry_irq_register:
 	instance->instancet->disable_intr(instance);
 	if (instance->msix_vectors)
 		for (i = 0; i < instance->msix_vectors; i++) {
-			irq_set_affinity_hint(
-				instance->msixentry[i].vector, NULL);
+			if (smp_affinity_enable)
+				irq_set_affinity_hint(
+					instance->msixentry[i].vector, NULL);
 			free_irq(instance->msixentry[i].vector,
 				 &instance->irq_context[i]);
 		}
@@ -5399,8 +5408,9 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	if (instance->msix_vectors)
 		for (i = 0; i < instance->msix_vectors; i++) {
-			irq_set_affinity_hint(
-				instance->msixentry[i].vector, NULL);
+			if (smp_affinity_enable)
+				irq_set_affinity_hint(
+					instance->msixentry[i].vector, NULL);
 			free_irq(instance->msixentry[i].vector,
 				 &instance->irq_context[i]);
 		}
@@ -5509,8 +5519,9 @@ megasas_resume(struct pci_dev *pdev)
 				printk(KERN_DEBUG "megasas: Failed to "
 				       "register IRQ for vector %d.\n", i);
 				for (j = 0; j < i; j++) {
-					irq_set_affinity_hint(
-						instance->msixentry[j].vector, NULL);
+					if (smp_affinity_enable)
+						irq_set_affinity_hint(
+							instance->msixentry[j].vector, NULL);
 					free_irq(
 						instance->msixentry[j].vector,
 						&instance->irq_context[j]);
@@ -5518,11 +5529,14 @@ megasas_resume(struct pci_dev *pdev)
 				goto fail_irq;
 			}
 
-			if (irq_set_affinity_hint(instance->msixentry[i].vector,
-				get_cpu_mask(cpu)))
-				dev_err(&instance->pdev->dev, "Error setting"
-					"affinity hint for cpu %d\n", cpu);
-			cpu = cpumask_next(cpu, cpu_online_mask);
+			if (smp_affinity_enable) {
+				if (irq_set_affinity_hint(instance->msixentry[i].vector,
+					get_cpu_mask(cpu)))
+					dev_err(&instance->pdev->dev, "Error "
+						"setting affinity hint for cpu "
+						"%d\n", cpu);
+				cpu = cpumask_next(cpu, cpu_online_mask);
+			}
 		}
 	} else {
 		instance->irq_context[0].instance = instance;
@@ -5640,8 +5654,9 @@ static void megasas_detach_one(struct pci_dev *pdev)
 
 	if (instance->msix_vectors)
 		for (i = 0; i < instance->msix_vectors; i++) {
-			irq_set_affinity_hint(
-				instance->msixentry[i].vector, NULL);
+			if (smp_affinity_enable)
+				irq_set_affinity_hint(
+					instance->msixentry[i].vector, NULL);
 			free_irq(instance->msixentry[i].vector,
 				 &instance->irq_context[i]);
 		}
@@ -5729,8 +5744,9 @@ static void megasas_shutdown(struct pci_dev *pdev)
 	instance->instancet->disable_intr(instance);
 	if (instance->msix_vectors)
 		for (i = 0; i < instance->msix_vectors; i++) {
-			irq_set_affinity_hint(
-				instance->msixentry[i].vector, NULL);
+			if (smp_affinity_enable)
+				irq_set_affinity_hint(
+					instance->msixentry[i].vector, NULL);
 			free_irq(instance->msixentry[i].vector,
 				 &instance->irq_context[i]);
 		}