[PATCH] drm/amdkfd: Differentiate logging message for driver oversubscription

[Felix Kuehling]

On 2024-10-28 17:40, Xiaogang.Chen wrote:
> From: Xiaogang Chen <xiaogang.chen at amd.com>
>
> To allow user better understand the cause triggering runlist oversubscription.
> No function change.
>
> Signed-off-by: Xiaogang Chen Xiaogang.Chen at amd.com
> ---
>   .../gpu/drm/amd/amdkfd/kfd_packet_manager.c   | 55 ++++++++++++++-----
>   1 file changed, 42 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> index 37930629edc5..e22be6da23b7 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_packet_manager.c
> @@ -28,6 +28,10 @@
>   #include "kfd_kernel_queue.h"
>   #include "kfd_priv.h"
>   
> +#define OVER_SUBSCRIPTION_PROCESS_COUNT 1 << 0
> +#define OVER_SUBSCRIPTION_COMPUTE_QUEUE_COUNT 1 << 1
> +#define OVER_SUBSCRIPTION_GWS_QUEUE_COUNT 1 << 2
> +
>   static inline void inc_wptr(unsigned int *wptr, unsigned int increment_bytes,
>   				unsigned int buffer_size_bytes)
>   {
> @@ -40,7 +44,7 @@ static inline void inc_wptr(unsigned int *wptr, unsigned int increment_bytes,
>   
>   static void pm_calc_rlib_size(struct packet_manager *pm,
>   				unsigned int *rlib_size,
> -				bool *over_subscription)
> +				int *over_subscription)
>   {
>   	unsigned int process_count, queue_count, compute_queue_count, gws_queue_count;
>   	unsigned int map_queue_size;
> @@ -58,17 +62,20 @@ static void pm_calc_rlib_size(struct packet_manager *pm,
>   	 * hws_max_conc_proc has been done in
>   	 * kgd2kfd_device_init().
>   	 */
> -	*over_subscription = false;
> +	*over_subscription = 0;
>   
>   	if (node->max_proc_per_quantum > 1)
>   		max_proc_per_quantum = node->max_proc_per_quantum;
>   
> -	if ((process_count > max_proc_per_quantum) ||
> -	    compute_queue_count > get_cp_queues_num(pm->dqm) ||
> -	    gws_queue_count > 1) {
> -		*over_subscription = true;
> +	if (process_count > max_proc_per_quantum)
> +		*over_subscription = *over_subscription || OVER_SUBSCRIPTION_PROCESS_COUNT;
> +	if (compute_queue_count > get_cp_queues_num(pm->dqm))
> +		*over_subscription = *over_subscription || OVER_SUBSCRIPTION_COMPUTE_QUEUE_COUNT;
> +	if (gws_queue_count > 1)
> +		*over_subscription = *over_subscription || OVER_SUBSCRIPTION_GWS_QUEUE_COUNT;
> +
> +	if (*over_subscription)
>   		dev_dbg(dev, "Over subscribed runlist\n");
> -	}
>   
>   	map_queue_size = pm->pmf->map_queues_size;
>   	/* calculate run list ib allocation size */
> @@ -89,7 +96,7 @@ static int pm_allocate_runlist_ib(struct packet_manager *pm,
>   				unsigned int **rl_buffer,
>   				uint64_t *rl_gpu_buffer,
>   				unsigned int *rl_buffer_size,
> -				bool *is_over_subscription)
> +				int *is_over_subscription)
>   {
>   	struct kfd_node *node = pm->dqm->dev;
>   	struct device *dev = node->adev->dev;
> @@ -134,7 +141,7 @@ static int pm_create_runlist_ib(struct packet_manager *pm,
>   	struct qcm_process_device *qpd;
>   	struct queue *q;
>   	struct kernel_queue *kq;
> -	bool is_over_subscription;
> +	int is_over_subscription;
>   
>   	rl_wptr = retval = processes_mapped = 0;
>   
> @@ -212,16 +219,38 @@ static int pm_create_runlist_ib(struct packet_manager *pm,
>   	dev_dbg(dev, "Finished map process and queues to runlist\n");
>   
>   	if (is_over_subscription) {
> -		if (!pm->is_over_subscription)
> -			dev_warn(
> +		if (!pm->is_over_subscription) {
> +
> +			if (is_over_subscription & OVER_SUBSCRIPTION_PROCESS_COUNT) {
> +				dev_warn(
>   				dev,
> -				"Runlist is getting oversubscribed. Expect reduced ROCm performance.\n");
> +				"process number is more than maximum number of processes that"
> +				" HWS can schedule concurrently. Runlist is getting"
> +				" oversubscribed. Expect reduced ROCm performance.\n");
> +			}
> +
> +			if (is_over_subscription & OVER_SUBSCRIPTION_COMPUTE_QUEUE_COUNT) {
> +				dev_warn(
> +				dev,
> +				"compute queue number is more than assigned compute queues."
> +				" Runlist is getting"
> +				" oversubscribed. Expect reduced ROCm performance.\n");
> +			}
> +
> +			if (is_over_subscription & OVER_SUBSCRIPTION_GWS_QUEUE_COUNT) {
> +				dev_warn(
> +				dev,
> +				"compute queue for cooperative workgroup is more than allowed."
> +				" Runlist is getting"
> +				" oversubscribed. Expect reduced ROCm performance.\n");
> +			}

I like the concept of showing the cause of oversubscription. Maybe we 
should add "process isolation mode" as a special case of "process count".

The messages are overly verbose. There is a common part of the message 
that could be printed if is_over_subscription is non-zero. Then just 
print some extra info about the cause, e.g.:

	if (is_over_subscription) {
		dev_warn("Runlist is getting oversubscribed due to%s%s%s. Expect reduced ROCm performance.\n",
			is_over_subscription & OVER_SUBSCRIPTION_PROCESS_COUNT ? " number-of-processes" : "",
			is_over_subscription & OVER_SUBSCRIPTION_COMPUTE_QUEUE_COUNT ? " number-of-queues" : "",
			is_over_subscription & OVER_SUBSCRIPTION_GWS_QUEUE_COUNT ? " cooperative-launch" : "");
	}

Regards,
   Felix


> +		}
>   		retval = pm->pmf->runlist(pm, &rl_buffer[rl_wptr],
>   					*rl_gpu_addr,
>   					alloc_size_bytes / sizeof(uint32_t),
>   					true);
>   	}
> -	pm->is_over_subscription = is_over_subscription;
> +	pm->is_over_subscription = is_over_subscription ? true : false;
>   
>   	for (i = 0; i < alloc_size_bytes / sizeof(uint32_t); i++)
>   		pr_debug("0x%2X ", rl_buffer[i]);