From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sreekanth Reddy Subject: [PATCH] [SCSI] mpt3sas: Added a driver module parameter max_msix_vectors Date: Wed, 14 Aug 2013 18:23:20 +0530 Message-ID: <20130814125320.GA3402@lsi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from mail-db8lp0186.outbound.messaging.microsoft.com ([213.199.154.186]:52495 "EHLO db8outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932315Ab3HNMxR (ORCPT ); Wed, 14 Aug 2013 08:53:17 -0400 Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: jejb@kernel.org, JBottomley@Parallels.com Cc: linux-scsi@vger.kernel.org, thenzl@redhat.com, Nagalakshmi.Nandigama@lsi.com, Sreekanth.Reddy@lsi.com 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 --- diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c index a32d63b..d40ba0b 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_base.c +++ b/drivers/scsi/mpt3sas/mpt3sas_base.c @@ -82,6 +82,10 @@ static int msix_disable = -1; 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, @@ -1723,6 +1727,16 @@ _base_enable_msix(struct MPT3SAS_ADAPTER *ioc) 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) {