Re: [bug report] NVMe/IB: reset_controller need more than 1min

[Sagi Grimberg <sagi@grimberg.me>]

>>> WDYT ? should we reconsider the "nvme connect --with_metadata" option ?
>>
>> Maybe you can make these lazily allocated?
> 
> You mean something like:
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index fd4720d37cc0..367ba0bb62ab 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1620,10 +1620,19 @@ int nvme_getgeo(struct block_device *bdev, 
> struct hd_geometry *geo)
>   }
> 
>   #ifdef CONFIG_BLK_DEV_INTEGRITY
> -static void nvme_init_integrity(struct gendisk *disk, u16 ms, u8 pi_type,
> -                               u32 max_integrity_segments)
> +static int nvme_init_integrity(struct gendisk *disk, struct nvme_ns *ns)
>   {
>          struct blk_integrity integrity = { };
> +       u16 ms = ns->ms;
> +       u8 pi_type = ns->pi_type;
> +       u32 max_integrity_segments = ns->ctrl->max_integrity_segments;
> +       int ret;
> +
> +       if (ns->ctrl->ops->init_integrity) {
> +               ret = ns->ctrl->ops->init_integrity(ns->ctrl);
> +               if (ret)
> +                       return ret;
> +       }
> 
>          switch (pi_type) {
>          case NVME_NS_DPS_PI_TYPE3:
> @@ -1644,11 +1653,13 @@ static void nvme_init_integrity(struct gendisk 
> *disk, u16 ms, u8 pi_type,
>          integrity.tuple_size = ms;
>          blk_integrity_register(disk, &integrity);
>          blk_queue_max_integrity_segments(disk->queue, 
> max_integrity_segments);
> +
> +       return 0;
>   }
>   #else
> -static void nvme_init_integrity(struct gendisk *disk, u16 ms, u8 pi_type,
> -                               u32 max_integrity_segments)
> +static void nvme_init_integrity(struct gendisk *disk, struct nvme_ns *ns)
>   {
> +       return 0;
>   }
>   #endif /* CONFIG_BLK_DEV_INTEGRITY */
> 
> @@ -1853,8 +1864,8 @@ static void nvme_update_disk_info(struct gendisk 
> *disk,
>          if (ns->ms) {
>                  if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
>                      (ns->features & NVME_NS_METADATA_SUPPORTED))
> -                       nvme_init_integrity(disk, ns->ms, ns->pi_type,
> - ns->ctrl->max_integrity_segments);
> +                       if (nvme_init_integrity(disk, ns))
> +                               capacity = 0;
>                  else if (!nvme_ns_has_pi(ns))
>                          capacity = 0;
>          }
> @@ -4395,7 +4406,7 @@ EXPORT_SYMBOL_GPL(nvme_stop_ctrl);
> 
> 
> and create the resources for the first namespace we find as PI formatted ?
> 
> 

I was thinking more along the lines of allocating it as soon as an I/O
comes with pi... Is there something internal to the driver that can
be done in parallel to expedite the allocation of these extra resources?