Re: [PATCH] iommu: Downgrade print level for iommu group information

[Robin Murphy <robin.murphy@arm.com>]

On 26/11/2024 7:23 am, Li RongQing wrote:
> This per device log is becoming longer with more and more PCI devices
> in system, which slows down the boot process due to the serializing
> nature of printk().
> 
> Downgrade dev_info() to dev_dbg() so it is still accessible for debug
> purposes.

Previously discussed 4 and a half years ago:

https://lore.kernel.org/linux-iommu/20200302154426.GC6540@8bytes.org/

Also, given that the iommu_probe_device() path is inherently serialised 
anyway, if logging a message from there significantly slows down your 
boot process, how slow is your console device?

Thanks,
Robin.

> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> ---
>   drivers/iommu/iommu.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 83c8e61..a16f944 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -1193,7 +1193,7 @@ static struct group_device *iommu_group_alloc_device(struct iommu_group *group,
>   
>   	trace_add_device_to_group(group->id, dev);
>   
> -	dev_info(dev, "Adding to iommu group %d\n", group->id);
> +	dev_dbg(dev, "Adding to iommu group %d\n", group->id);
>   
>   	return device;
>