Re: [PATCH 09/11] megaraid_sas: switch fusion adapters to MQ

[John Garry <john.garry@huawei.com>]

On 09/12/2019 10:10, Sumit Saxena wrote:
> On Mon, Dec 2, 2019 at 9:09 PM Hannes Reinecke <hare@suse.de> wrote:
>>
>> Fusion adapters can steer completions to individual queues, and
>> we now have support for shared host-wide tags.
>> So we can enable multiqueue support for fusion adapters and
>> drop the hand-crafted interrupt affinity settings.
> 
> Hi Hannes,
> 
> Ming Lei also proposed similar changes in megaraid_sas driver some
> time back and it had resulted in performance drop-
> https://patchwork.kernel.org/patch/10969511/
> 
> So, we will do some performance tests with this patch and update you.
> 

Hi Sumit,

I was wondering if you had a chance to do this test yet?

It would be good to know, so we can try to progress this work.

@Hannes, This shared sbitmap work now seems to conflict with Jens work 
on tag caching 
https://lore.kernel.org/linux-block/20200107163037.31745-1-axboe@kernel.dk/T/#t, 
but should be resolvable AFAICS (v1, anyway, which I checked). Anway, we 
seem to have stalled, which I feared...

Thanks,
John

> Thanks,
> Sumit
>>
>> Signed-off-by: Hannes Reinecke <hare@suse.com>
>> ---
>>   drivers/scsi/megaraid/megaraid_sas.h        |  1 -
>>   drivers/scsi/megaraid/megaraid_sas_base.c   | 65 +++++++++--------------------
>>   drivers/scsi/megaraid/megaraid_sas_fusion.c | 14 ++++---
>>   3 files changed, 28 insertions(+), 52 deletions(-)
>>
>> diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
>> index bd8184072bed..844ea2d6dbb8 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas.h
>> +++ b/drivers/scsi/megaraid/megaraid_sas.h
>> @@ -2261,7 +2261,6 @@ enum MR_PERF_MODE {
>>
>>   struct megasas_instance {
>>
>> -       unsigned int *reply_map;
>>          __le32 *producer;
>>          dma_addr_t producer_h;
>>          __le32 *consumer;
>> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
>> index a4bc81479284..9d0d74e3d491 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas_base.c
>> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c
>> @@ -37,6 +37,7 @@
>>   #include <linux/poll.h>
>>   #include <linux/vmalloc.h>
>>   #include <linux/irq_poll.h>
>> +#include <linux/blk-mq-pci.h>
>>
>>   #include <scsi/scsi.h>
>>   #include <scsi/scsi_cmnd.h>
>> @@ -3106,6 +3107,19 @@ megasas_bios_param(struct scsi_device *sdev, struct block_device *bdev,
>>          return 0;
>>   }
>>
>> +static int megasas_map_queues(struct Scsi_Host *shost)
>> +{
>> +       struct megasas_instance *instance;
>> +
>> +       instance = (struct megasas_instance *)shost->hostdata;
>> +
>> +       if (!instance->smp_affinity_enable)
>> +               return 0;
>> +
>> +       return blk_mq_pci_map_queues(&shost->tag_set.map[HCTX_TYPE_DEFAULT],
>> +                       instance->pdev, instance->low_latency_index_start);
>> +}
>> +
>>   static void megasas_aen_polling(struct work_struct *work);
>>
>>   /**
>> @@ -3414,9 +3428,11 @@ static struct scsi_host_template megasas_template = {
>>          .eh_timed_out = megasas_reset_timer,
>>          .shost_attrs = megaraid_host_attrs,
>>          .bios_param = megasas_bios_param,
>> +       .map_queues = megasas_map_queues,
>>          .change_queue_depth = scsi_change_queue_depth,
>>          .max_segment_size = 0xffffffff,
>>          .no_write_same = 1,
>> +       .host_tagset = 1,
>>   };
>>
>>   /**
>> @@ -5695,34 +5711,6 @@ megasas_setup_jbod_map(struct megasas_instance *instance)
>>                  instance->use_seqnum_jbod_fp = false;
>>   }
>>
>> -static void megasas_setup_reply_map(struct megasas_instance *instance)
>> -{
>> -       const struct cpumask *mask;
>> -       unsigned int queue, cpu, low_latency_index_start;
>> -
>> -       low_latency_index_start = instance->low_latency_index_start;
>> -
>> -       for (queue = low_latency_index_start; queue < instance->msix_vectors; queue++) {
>> -               mask = pci_irq_get_affinity(instance->pdev, queue);
>> -               if (!mask)
>> -                       goto fallback;
>> -
>> -               for_each_cpu(cpu, mask)
>> -                       instance->reply_map[cpu] = queue;
>> -       }
>> -       return;
>> -
>> -fallback:
>> -       queue = low_latency_index_start;
>> -       for_each_possible_cpu(cpu) {
>> -               instance->reply_map[cpu] = queue;
>> -               if (queue == (instance->msix_vectors - 1))
>> -                       queue = low_latency_index_start;
>> -               else
>> -                       queue++;
>> -       }
>> -}
>> -
>>   /**
>>    * megasas_get_device_list -   Get the PD and LD device list from FW.
>>    * @instance:                  Adapter soft state
>> @@ -6021,12 +6009,6 @@ static int megasas_init_fw(struct megasas_instance *instance)
>>                                          instance->is_rdpq = (scratch_pad_1 & MR_RDPQ_MODE_OFFSET) ?
>>                                                                  1 : 0;
>>
>> -                               if (instance->adapter_type >= INVADER_SERIES &&
>> -                                   !instance->msix_combined) {
>> -                                       instance->msix_load_balance = true;
>> -                                       instance->smp_affinity_enable = false;
>> -                               }
>> -
>>                                  /* Save 1-15 reply post index address to local memory
>>                                   * Index 0 is already saved from reg offset
>>                                   * MPI2_REPLY_POST_HOST_INDEX_OFFSET
>> @@ -6145,8 +6127,6 @@ static int megasas_init_fw(struct megasas_instance *instance)
>>                          goto fail_init_adapter;
>>          }
>>
>> -       megasas_setup_reply_map(instance);
>> -
>>          dev_info(&instance->pdev->dev,
>>                  "current msix/online cpus\t: (%d/%d)\n",
>>                  instance->msix_vectors, (unsigned int)num_online_cpus());
>> @@ -6780,6 +6760,9 @@ static int megasas_io_attach(struct megasas_instance *instance)
>>          host->max_id = MEGASAS_MAX_DEV_PER_CHANNEL;
>>          host->max_lun = MEGASAS_MAX_LUN;
>>          host->max_cmd_len = 16;
>> +       if (instance->adapter_type != MFI_SERIES && instance->msix_vectors > 0)
>> +               host->nr_hw_queues = instance->msix_vectors -
>> +                       instance->low_latency_index_start;
>>
>>          /*
>>           * Notify the mid-layer about the new controller
>> @@ -6947,11 +6930,6 @@ static inline int megasas_alloc_mfi_ctrl_mem(struct megasas_instance *instance)
>>    */
>>   static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>>   {
>> -       instance->reply_map = kcalloc(nr_cpu_ids, sizeof(unsigned int),
>> -                                     GFP_KERNEL);
>> -       if (!instance->reply_map)
>> -               return -ENOMEM;
>> -
>>          switch (instance->adapter_type) {
>>          case MFI_SERIES:
>>                  if (megasas_alloc_mfi_ctrl_mem(instance))
>> @@ -6968,8 +6946,6 @@ static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>>
>>          return 0;
>>    fail:
>> -       kfree(instance->reply_map);
>> -       instance->reply_map = NULL;
>>          return -ENOMEM;
>>   }
>>
>> @@ -6982,7 +6958,6 @@ static int megasas_alloc_ctrl_mem(struct megasas_instance *instance)
>>    */
>>   static inline void megasas_free_ctrl_mem(struct megasas_instance *instance)
>>   {
>> -       kfree(instance->reply_map);
>>          if (instance->adapter_type == MFI_SERIES) {
>>                  if (instance->producer)
>>                          dma_free_coherent(&instance->pdev->dev, sizeof(u32),
>> @@ -7645,8 +7620,6 @@ megasas_resume(struct pci_dev *pdev)
>>          if (rval < 0)
>>                  goto fail_reenable_msix;
>>
>> -       megasas_setup_reply_map(instance);
>> -
>>          if (instance->adapter_type != MFI_SERIES) {
>>                  megasas_reset_reply_desc(instance);
>>                  if (megasas_ioc_init_fusion(instance)) {
>> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> index e301458bcbae..bae96b82bb10 100644
>> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
>> @@ -2731,6 +2731,7 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
>>          struct MR_PRIV_DEVICE *mrdev_priv;
>>          struct RAID_CONTEXT *rctx;
>>          struct RAID_CONTEXT_G35 *rctx_g35;
>> +       u32 tag = blk_mq_unique_tag(scp->request);
>>
>>          device_id = MEGASAS_DEV_INDEX(scp);
>>
>> @@ -2837,7 +2838,7 @@ megasas_build_ldio_fusion(struct megasas_instance *instance,
>>                                      instance->msix_vectors));
>>          else
>>                  cmd->request_desc->SCSIIO.MSIxIndex =
>> -                       instance->reply_map[raw_smp_processor_id()];
>> +                       blk_mq_unique_tag_to_hwq(tag);
>>
>>          if (instance->adapter_type >= VENTURA_SERIES) {
>>                  /* FP for Optimal raid level 1.
>> @@ -3080,6 +3081,7 @@ megasas_build_syspd_fusion(struct megasas_instance *instance,
>>          u16 pd_index = 0;
>>          u16 os_timeout_value;
>>          u16 timeout_limit;
>> +       u32 tag = blk_mq_unique_tag(scmd->request);
>>          struct MR_DRV_RAID_MAP_ALL *local_map_ptr;
>>          struct RAID_CONTEXT     *pRAID_Context;
>>          struct MR_PD_CFG_SEQ_NUM_SYNC *pd_sync;
>> @@ -3169,7 +3171,7 @@ megasas_build_syspd_fusion(struct megasas_instance *instance,
>>                                      instance->msix_vectors));
>>          else
>>                  cmd->request_desc->SCSIIO.MSIxIndex =
>> -                       instance->reply_map[raw_smp_processor_id()];
>> +                       blk_mq_unique_tag_to_hwq(tag);
>>
>>          if (!fp_possible) {
>>                  /* system pd firmware path */
>> @@ -3373,7 +3375,7 @@ megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
>>   {
>>          struct megasas_cmd_fusion *cmd, *r1_cmd = NULL;
>>          union MEGASAS_REQUEST_DESCRIPTOR_UNION *req_desc;
>> -       u32 index;
>> +       u32 index, blk_tag, unique_tag;
>>
>>          if ((megasas_cmd_type(scmd) == READ_WRITE_LDIO) &&
>>                  instance->ldio_threshold &&
>> @@ -3389,7 +3391,9 @@ megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
>>                  return SCSI_MLQUEUE_HOST_BUSY;
>>          }
>>
>> -       cmd = megasas_get_cmd_fusion(instance, scmd->request->tag);
>> +       unique_tag = blk_mq_unique_tag(scmd->request);
>> +       blk_tag = blk_mq_unique_tag_to_tag(unique_tag);
>> +       cmd = megasas_get_cmd_fusion(instance, blk_tag);
>>
>>          if (!cmd) {
>>                  atomic_dec(&instance->fw_outstanding);
>> @@ -3430,7 +3434,7 @@ megasas_build_and_issue_cmd_fusion(struct megasas_instance *instance,
>>           */
>>          if (cmd->r1_alt_dev_handle != MR_DEVHANDLE_INVALID) {
>>                  r1_cmd = megasas_get_cmd_fusion(instance,
>> -                               (scmd->request->tag + instance->max_fw_cmds));
>> +                               (blk_tag + instance->max_fw_cmds));
>>                  megasas_prepare_secondRaid1_IO(instance, cmd, r1_cmd);
>>          }
>>
>> --
>> 2.16.4
>>
> .
>