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authorMartin K. Petersen <martin.petersen@oracle.com>2014-01-03 19:16:55 -0500
committerChristoph Hellwig <hch@lst.de>2014-07-25 17:16:58 -0400
commitcbbb7b31ad842e17b690254a546ddcedc79a4f05 (patch)
tree903f4718dfa6002c05e615515d5e4321fdbe7124 /drivers/scsi
parent9f21316fc2f297efd32b40a57083d5cecb4bda26 (diff)
mpt2sas: Rework the MSI-X grouping code
On systems with a non power-of-two CPU count the existing MSI-X grouping code failed to distribute interrupts correctly. Rework the code to handle arbitrary processor counts. Also remove the hardcoded upper limit on the number of processors so we can boot on large systems. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Sreekanth Reddy <Sreekanth.reddy@avagotech.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/mpt2sas/mpt2sas_base.c64
1 files changed, 23 insertions, 41 deletions
diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index a31397c1f16e..92a1f19437a5 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -1332,53 +1332,35 @@ _base_request_irq(struct MPT2SAS_ADAPTER *ioc, u8 index, u32 vector)
static void
_base_assign_reply_queues(struct MPT2SAS_ADAPTER *ioc)
{
- struct adapter_reply_queue *reply_q;
- int cpu_id;
- int cpu_grouping, loop, grouping, grouping_mod;
+ unsigned int cpu, nr_cpus, nr_msix, index = 0;
if (!_base_is_controller_msix_enabled(ioc))
return;
memset(ioc->cpu_msix_table, 0, ioc->cpu_msix_table_sz);
- /* when there are more cpus than available msix vectors,
- * then group cpus togeather on same irq
- */
- if (ioc->cpu_count > ioc->msix_vector_count) {
- grouping = ioc->cpu_count / ioc->msix_vector_count;
- grouping_mod = ioc->cpu_count % ioc->msix_vector_count;
- if (grouping < 2 || (grouping == 2 && !grouping_mod))
- cpu_grouping = 2;
- else if (grouping < 4 || (grouping == 4 && !grouping_mod))
- cpu_grouping = 4;
- else if (grouping < 8 || (grouping == 8 && !grouping_mod))
- cpu_grouping = 8;
- else
- cpu_grouping = 16;
- } else
- cpu_grouping = 0;
-
- loop = 0;
- reply_q = list_entry(ioc->reply_queue_list.next,
- struct adapter_reply_queue, list);
- for_each_online_cpu(cpu_id) {
- if (!cpu_grouping) {
- ioc->cpu_msix_table[cpu_id] = reply_q->msix_index;
- reply_q = list_entry(reply_q->list.next,
- struct adapter_reply_queue, list);
- } else {
- if (loop < cpu_grouping) {
- ioc->cpu_msix_table[cpu_id] =
- reply_q->msix_index;
- loop++;
- } else {
- reply_q = list_entry(reply_q->list.next,
- struct adapter_reply_queue, list);
- ioc->cpu_msix_table[cpu_id] =
- reply_q->msix_index;
- loop = 1;
- }
+
+ nr_cpus = num_online_cpus();
+ nr_msix = ioc->reply_queue_count = min(ioc->reply_queue_count,
+ ioc->facts.MaxMSIxVectors);
+ if (!nr_msix)
+ return;
+
+ cpu = cpumask_first(cpu_online_mask);
+
+ do {
+ unsigned int i, group = nr_cpus / nr_msix;
+
+ if (index < nr_cpus % nr_msix)
+ group++;
+
+ for (i = 0 ; i < group ; i++) {
+ ioc->cpu_msix_table[cpu] = index;
+ cpu = cpumask_next(cpu, cpu_online_mask);
}
- }
+
+ index++;
+
+ } while (cpu < nr_cpus);
}
/**