Re: [PATCH v11 05/31] cxl/mem: Expose dynamic ram 1 partition in sysfs

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Empty sysfs directory created for absent dynamic RAM partitions.
--

commit 839299dd9514d54314e661cd789de765da08d4f4
Author: Ira Weiny <iweiny@kernel.org>

cxl/mem: Expose dynamic ram 1 partition in sysfs

This commit exposes the details of the first dynamic ram partition via
sysfs so user space can properly configure CXL regions.

> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c

[ ... ]

> @@ -519,6 +551,29 @@ static struct attribute_group cxl_memdev_pmem_attribute_group = {
>  	.is_visible = cxl_pmem_visible,
>  };
>  
> +static umode_t cxl_dynamic_ram_1_visible(struct kobject *kobj, struct attribute *a, int n)
> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
> +	struct cxl_dpa_perf *perf = part_perf(cxlmd->cxlds, CXL_PARTMODE_DYNAMIC_RAM_1);
> +
> +	if (a == &dev_attr_dynamic_ram_1_qos_class.attr &&
> +	    (!perf || perf->qos_class == CXL_QOS_CLASS_INVALID))
> +		return 0;
> +
> +	if (a == &dev_attr_dynamic_ram_1_size.attr &&
> +	    (!cxl_part_size(cxlmd->cxlds, CXL_PARTMODE_DYNAMIC_RAM_1)))
> +		return 0;

[Severity: Low]
Should cxl_dynamic_ram_1_visible() return SYSFS_GROUP_INVISIBLE here when the
dynamic RAM partition is absent?

Since cxl_memdev_dynamic_ram_1_attribute_group is a named group
(.name = "dynamic_ram_1"), returning 0 hides the individual attributes but
still creates the group directory.

Won't this result in a permanently empty "dynamic_ram_1" directory in sysfs if
the size is 0, rather than suppressing the directory entirely?

> +
> +	return a->mode;
> +}
> +
> +static struct attribute_group cxl_memdev_dynamic_ram_1_attribute_group = {
> +	.name = "dynamic_ram_1",
> +	.attrs = cxl_memdev_dynamic_ram_1_attributes,
> +	.is_visible = cxl_dynamic_ram_1_visible,
> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260625112638.550691-1-anisa.su@samsung.com?part=5