[SCSI] mpt3sas: Added a driver module parameter max_msix_vectors
Added a driver module parameter max_msix_vectors. Using this module parameter
the maximum number of MSI-X vectors could be set.
The number of MSI-X vectors used would be the minimum of MSI-X vectors
supported by the HBA, the number of CPU cores and the value set to
max_msix_vectors module parameter.
The default value of this module parameter is set to 8. The default value of
this parameter is set to 8 inorder to reduce the amount of memory required for
Reply Descriptor Post queue. This is because with the higher MSI-X vectors,
some times kernel is not able to allocate the requested amount of memory and
crash is observed. To overcome this problem, the default value is set to 8.
Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 34ff896..fa78506 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -82,6 +82,10 @@
module_param(msix_disable, int, 0);
MODULE_PARM_DESC(msix_disable, " disable msix routed interrupts (default=0)");
+static int max_msix_vectors = 8;
+module_param(max_msix_vectors, int, 0);
+MODULE_PARM_DESC(max_msix_vectors,
+ " max msix vectors - (default=8)");
static int mpt3sas_fwfault_debug;
MODULE_PARM_DESC(mpt3sas_fwfault_debug,
@@ -1721,6 +1725,16 @@
ioc->reply_queue_count = min_t(int, ioc->cpu_count,
ioc->msix_vector_count);
+ printk(MPT3SAS_FMT "MSI-X vectors supported: %d, no of cores"
+ ": %d, max_msix_vectors: %d\n", ioc->name, ioc->msix_vector_count,
+ ioc->cpu_count, max_msix_vectors);
+
+ if (max_msix_vectors > 0) {
+ ioc->reply_queue_count = min_t(int, max_msix_vectors,
+ ioc->reply_queue_count);
+ ioc->msix_vector_count = ioc->reply_queue_count;
+ }
+
entries = kcalloc(ioc->reply_queue_count, sizeof(struct msix_entry),
GFP_KERNEL);
if (!entries) {