Re: [PATCH] accel/ivpu: use kmem_cache for IPC rx_msg allocations

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Duplicate kmem_cache name on multi-device systems
--

commit 41c16409be6704d2ef5ab21270390fee65dcf7aa
Author: Karol Wachowski <karol.wachowski@linux.intel.com>

accel/ivpu: use kmem_cache for IPC rx_msg allocations

This commit introduces a dedicated kmem_cache for allocating IPC rx_msg
objects to reduce allocator overhead in IRQ handlers.

> diff --git a/drivers/accel/ivpu/ivpu_ipc.c b/drivers/accel/ivpu/ivpu_ipc.c
> --- a/drivers/accel/ivpu/ivpu_ipc.c
> +++ b/drivers/accel/ivpu/ivpu_ipc.c

[ ... ]

> @@ -490,10 +490,18 @@ int ivpu_ipc_init(struct ivpu_device *vdev)
>  	struct ivpu_ipc_info *ipc = vdev->ipc;
>  	int ret;
>  
> +	ipc->rx_msg_cache = kmem_cache_create("ivpu_ipc_rx_msg", sizeof(struct ivpu_ipc_rx_msg), 0,
> +					      SLAB_HWCACHE_ALIGN, NULL);

[Severity: Medium]
Will this cause a name collision if there are multiple ivpu devices in the
same system?

Since this is initialized per-device in ivpu_ipc_init(), calling
kmem_cache_create() multiple times with the same hardcoded string
"ivpu_ipc_rx_msg" can trigger a kernel WARN in kmem_cache_sanity_check()
when CONFIG_DEBUG_VM is enabled.

Furthermore, if SLUB merging is disabled via boot parameters or config,
the duplicate name causes a sysfs kobject collision, leading to a sysfs
warning and a failure to register the cache in sysfs.

Should this cache name be made unique per device using dev_name(), or 
should the cache be a global singleton?

> +	if (!ipc->rx_msg_cache) {
> +		ivpu_err(vdev, "Failed to create rx_msg_cache\n");
> +		return -ENOMEM;
> +	}
> +
>  	ipc->mem_tx = ivpu_bo_create_global(vdev, SZ_16K, DRM_IVPU_BO_WC | DRM_IVPU_BO_MAPPABLE);
>  	if (!ipc->mem_tx) {
>  		ivpu_err(vdev, "Failed to allocate mem_tx\n");
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto err_destroy_cache;
>  	}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611055214.948748-1-karol.wachowski@linux.intel.com?part=1