On Mon, Aug 07, 2017 at 09:39:59AM -0700, Dave Jiang wrote:
> +static int queue_mode = PMEM_Q_MQ;
So this changes the default for everyone. How about those systems
without dma engine?
> module_param(queue_mode, int, 0444);
> -MODULE_PARM_DESC(queue_mode, "Pmem Queue Mode (0=BIO, 1=BLK-MQ)");
> +MODULE_PARM_DESC(queue_mode, "Pmem Queue Mode (0=BIO, 1=BLK-MQ & DMA)");
> +
> +static int queue_depth = 128;
> +module_param(queue_depth, int, 0444);
> +MODULE_PARM_DESC(queue_depth, "I/O Queue Depth for multi queue mode");
This changes the default from the previous patch, why not introduce
this parameter and default there. And an explanation of the magic
value would still be nice.
> +/* typically maps to number of DMA channels/devices per socket */
> +static int q_per_node = 8;
> +module_param(q_per_node, int, 0444);
> +MODULE_PARM_DESC(q_per_node, "Hardware queues per node\n");
How can a fixed constant "typically map" to a hardware dependent
resource?
> + if (res) {
unlikely?
> + enum dmaengine_tx_result dma_err = res->result;
> +
> + switch (dma_err) {
do you really need the local variable for a single check of it?
> + case DMA_TRANS_READ_FAILED:
> + case DMA_TRANS_WRITE_FAILED:
> + case DMA_TRANS_ABORTED:
> + dev_dbg(dev, "bio failed\n");
> + rc = -ENXIO;
> + break;
> + case DMA_TRANS_NOERROR:
> + default:
> + break;
> + }
> + }
> +
> + if (req->cmd_flags & REQ_FUA)
> + nvdimm_flush(nd_region);
> +
> + blk_mq_end_request(cmd->rq, rc);
blk_mq_end_request takes a blk_status_t. Note that sparse would
have caught that, so please run your code through sparse.
> + if (cmd->sg_nents > 128) {
WARN_ON_ONCE as this should not happen.
> + if (queue_mode == PMEM_Q_MQ) {
> pmem->tag_set.ops = &pmem_mq_ops;
> - pmem->tag_set.nr_hw_queues = nr_online_nodes;
> - pmem->tag_set.queue_depth = 64;
> + pmem->tag_set.nr_hw_queues = nr_online_nodes * q_per_node;
> + pmem->tag_set.queue_depth = queue_depth;
please use present nodes - we don't remap on cpu soft online/offline.
> pmem->tag_set.numa_node = dev_to_node(dev);
> - pmem->tag_set.cmd_size = sizeof(struct pmem_cmd);
> + pmem->tag_set.cmd_size = sizeof(struct pmem_cmd) +
> + sizeof(struct scatterlist) * 128;
s/128/queue_depth/
> pmem->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
> pmem->tag_set.driver_data = pmem;
>
> @@ -466,7 +649,11 @@ static int pmem_attach_disk(struct device *dev,
> blk_queue_write_cache(pmem->q, wbc, fua);
> blk_queue_physical_block_size(pmem->q, PAGE_SIZE);
> blk_queue_logical_block_size(pmem->q, pmem_sector_size(ndns));
> - blk_queue_max_hw_sectors(pmem->q, UINT_MAX);
> + if (queue_mode == PMEM_Q_MQ) {
> + blk_queue_max_hw_sectors(pmem->q, 0x200000);
> + blk_queue_max_segments(pmem->q, 128);
Where do these magic numbers come from?
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