From 91b265bf0b5733a6c4865e809c93a2a812de46e8 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 3 Jan 2014 19:16:56 -0500 Subject: [PATCH] mpt3sas: 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 Acked-by: Sreekanth Reddy Signed-off-by: Christoph Hellwig --- drivers/scsi/mpt3sas/mpt3sas_base.c | 73 +++++++++++-------------------------- 1 file changed, 21 insertions(+), 52 deletions(-) diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index 0cf4f70..c608a61 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -1624,66 +1624,35 @@ _base_request_irq(struct MPT3SAS_ADAPTER *ioc, u8 index, u32 vector) static void _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc) { - struct adapter_reply_queue *reply_q; - int cpu_id; - int cpu_grouping, loop, grouping, grouping_mod; - int reply_queue; + 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); - /* NUMA Hardware bug workaround - drop to less reply queues */ - if (ioc->reply_queue_count > ioc->facts.MaxMSIxVectors) { - ioc->reply_queue_count = ioc->facts.MaxMSIxVectors; - reply_queue = 0; - list_for_each_entry(reply_q, &ioc->reply_queue_list, list) { - reply_q->msix_index = reply_queue; - if (++reply_queue == ioc->reply_queue_count) - reply_queue = 0; - } - } + nr_cpus = num_online_cpus(); + nr_msix = ioc->reply_queue_count = min(ioc->reply_queue_count, + ioc->facts.MaxMSIxVectors); + if (!nr_msix) + return; - /* 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; - } + 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); } /** -- 2.7.4