[PATCH V4] drm/xe/uapi: Use hint for guc to set GT frequency

Belgaumkar, Vinay vinay.belgaumkar at intel.com
Thu Jan 23 23:24:08 UTC 2025


On 1/21/2025 8:26 AM, Rodrigo Vivi wrote:
> On Tue, Jan 21, 2025 at 06:46:05PM +0530, Tejas Upadhyay wrote:
>> Allow user to provide a low latency hint. When set,
>> KMD sends a hint to GuC which results in special handling for that process.
>> SLPC will ramp the GT frequency aggressively every time
>> it switches to this process.
>>
>> We need to enable the use of SLPC Compute strategy during init, but
>> it will apply only to processes that set this bit during process
>> creation.
>>
>> Improvement with this approach as below:
>>
>> Before,
>>
>> :~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency
>> Platform: Intel(R) OpenCL Graphics
>>    Device: Intel(R) Graphics [0xe20b]
>>      Driver version  : 24.52.0 (Linux x64)
>>      Compute units   : 160
>>      Clock frequency : 2850 MHz
>>      Kernel launch latency : 283.16 us
>>
>> After,
>>
>> :~$ NEOReadDebugKeys=1 EnableDirectSubmission=0 clpeak --kernel-latency
>> Platform: Intel(R) OpenCL Graphics
>>    Device: Intel(R) Graphics [0xe20b]
>>      Driver version  : 24.52.0 (Linux x64)
>>      Compute units   : 160
>>      Clock frequency : 2850 MHz
>>
>>      Kernel launch latency : 63.38 us
>>
>> UMD will indicate low latency hint with flag as mentioned below,
>>
>> *     struct drm_xe_exec_queue_create exec_queue_create = {
>> *          .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT or 0
> or 0 ?!
>
>> *          .extensions = 0,
>> *          .vm_id = vm,
>> *          .num_bb_per_exec = 1,
>> *          .num_eng_per_bb = 1,
>> *          .instances = to_user_pointer(&instance),
>> *     };
>> *     ioctl(fd, DRM_IOCTL_XE_EXEC_QUEUE_CREATE, &exec_queue_create);
> What about moving this block to the uapi documentation?
> we shouldn't miss a good opportunity to document our uapi ;)
>
>> Link to UMD PR : https://github.com/intel/compute-runtime/pull/794
>>
>> V4:
>>    - To make it clear, dont use exec queue word (Vinay)
>>    - Correct typo in description of flag (Jose/Vinay)
>>    - rename set_strategy api and replace ctx with exec queue(Vinay)
>>    - Start with 0th bit to indentify user flags (Jose)
>> V3:
>>    - Conver user flag to kernel internal flag and use (Oak)
>>    - Support query config for use to check kernel support (Jose)
>>    - Dont need to take runtime pm (Vinay)
>> V2:
>>    - DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT 1 is already planned for other hint(Szymon)
>>    - Add motivation to description (Lucas)
>>
>> Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
>> ---
>>   drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h |  3 +++
>>   drivers/gpu/drm/xe/xe_exec_queue.c            | 11 ++++++++---
>>   drivers/gpu/drm/xe/xe_exec_queue_types.h      |  3 ++-
>>   drivers/gpu/drm/xe/xe_guc_pc.c                | 16 ++++++++++++++++
>>   drivers/gpu/drm/xe/xe_guc_submit.c            |  8 ++++++++
>>   drivers/gpu/drm/xe/xe_query.c                 |  3 ++-
>>   include/uapi/drm/xe_drm.h                     |  7 ++++++-
>>   7 files changed, 45 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h b/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
>> index 85abe4f09ae2..c50075b8270f 100644
>> --- a/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
>> +++ b/drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h
>> @@ -174,6 +174,9 @@ struct slpc_task_state_data {
>>   	};
>>   } __packed;
>>   
>> +#define SLPC_EXEC_QUEUE_FREQ_REQ_IS_COMPUTE	REG_BIT(28)
> I understand why you did that, but I don't believe we should use Xe
> terminology in the GuC ABI... It should follow the SLPC naming and
> likely SLPC_CTX_FREQ_REQ_IS_COMPUTE seems the right choice here...
>
> Vinay?! thoughts?

yup, should be GuC ABI specific. Should be SLPC_CTX_FREQ_REQ_IS_COMPUTE.

Thanks,

Vinay.

>
>> +#define SLPC_OPTIMIZED_STRATEGY_COMPUTE		REG_BIT(0)
>> +
>>   struct slpc_shared_data_header {
>>   	/* Total size in bytes of this shared buffer. */
>>   	u32 size;
>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
>> index 8948f50ee58f..bd33fb318677 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>> @@ -544,6 +544,7 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>>   	struct drm_xe_engine_class_instance __user *user_eci =
>>   		u64_to_user_ptr(args->instances);
>>   	struct xe_hw_engine *hwe;
>> +	unsigned long flags;
>>   	struct xe_vm *vm;
>>   	struct xe_gt *gt;
>>   	struct xe_tile *tile;
>> @@ -553,7 +554,8 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>>   	u32 len;
>>   	int err;
>>   
>> -	if (XE_IOCTL_DBG(xe, args->flags) ||
>> +	if (XE_IOCTL_DBG(xe, args->flags &&
>> +			 !(args->flags & DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT)) ||
>>   	    XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
>>   		return -EINVAL;
>>   
>> @@ -570,6 +572,9 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>>   	if (XE_IOCTL_DBG(xe, eci[0].gt_id >= xe->info.gt_count))
>>   		return -EINVAL;
>>   
>> +	if (args->flags & DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT)
>> +		flags |= EXEC_QUEUE_FLAG_LOW_LATENCY;
>> +
>>   	if (eci[0].engine_class == DRM_XE_ENGINE_CLASS_VM_BIND) {
>>   		if (XE_IOCTL_DBG(xe, args->width != 1) ||
>>   		    XE_IOCTL_DBG(xe, args->num_placements != 1) ||
>> @@ -578,8 +583,8 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>>   
>>   		for_each_tile(tile, xe, id) {
>>   			struct xe_exec_queue *new;
>> -			u32 flags = EXEC_QUEUE_FLAG_VM;
>>   
>> +			flags |= EXEC_QUEUE_FLAG_VM;
>>   			if (id)
>>   				flags |= EXEC_QUEUE_FLAG_BIND_ENGINE_CHILD;
>>   
>> @@ -626,7 +631,7 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>>   		}
>>   
>>   		q = xe_exec_queue_create(xe, vm, logical_mask,
>> -					 args->width, hwe, 0,
>> +					 args->width, hwe, flags,
>>   					 args->extensions);
>>   		up_read(&vm->lock);
>>   		xe_vm_put(vm);
>> diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> index 5af5419cec7a..30dc129a6b09 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> @@ -85,7 +85,8 @@ struct xe_exec_queue {
>>   #define EXEC_QUEUE_FLAG_BIND_ENGINE_CHILD	BIT(3)
>>   /* kernel exec_queue only, set priority to highest level */
>>   #define EXEC_QUEUE_FLAG_HIGH_PRIORITY		BIT(4)
>> -
>> +/* flag to indicate low latency hint to guc */
>> +#define EXEC_QUEUE_FLAG_LOW_LATENCY		BIT(5)
>>   	/**
>>   	 * @flags: flags for this exec queue, should statically setup aside from ban
>>   	 * bit
>> diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
>> index 44b5211066ef..e926f89e4ce9 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
>> @@ -1014,6 +1014,17 @@ static int slpc_set_policies(struct xe_guc_pc *pc)
>>   	return 0;
>>   }
>>   
>> +static int pc_action_set_strategy(struct xe_guc_pc *pc, u32 val)
>> +{
>> +	int ret = 0;
>> +
>> +	ret = pc_action_set_param(pc,
>> +				  SLPC_PARAM_STRATEGIES,
>> +				  val);
>> +
>> +	return ret;
>> +}
>> +
>>   /**
>>    * xe_guc_pc_start - Start GuC's Power Conservation component
>>    * @pc: Xe_GuC_PC instance
>> @@ -1077,6 +1088,11 @@ int xe_guc_pc_start(struct xe_guc_pc *pc)
>>   	}
>>   
>>   	ret = pc_action_setup_gucrc(pc, GUCRC_FIRMWARE_CONTROL);
>> +	if (ret)
>> +		goto out;
>> +
>> +	/* Enable SLPC Optimized Strategy for compute */
>> +	ret = pc_action_set_strategy(pc, SLPC_OPTIMIZED_STRATEGY_COMPUTE);
>>   
>>   out:
>>   	xe_force_wake_put(gt_to_fw(gt), fw_ref);
>> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
>> index 913c74d6e2ae..be7551756eb9 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
>> @@ -15,6 +15,7 @@
>>   #include <drm/drm_managed.h>
>>   
>>   #include "abi/guc_actions_abi.h"
>> +#include "abi/guc_actions_slpc_abi.h"
>>   #include "abi/guc_klvs_abi.h"
>>   #include "regs/xe_lrc_layout.h"
>>   #include "xe_assert.h"
>> @@ -400,6 +401,7 @@ static void __guc_exec_queue_policy_add_##func(struct exec_queue_policy *policy,
>>   MAKE_EXEC_QUEUE_POLICY_ADD(execution_quantum, EXECUTION_QUANTUM)
>>   MAKE_EXEC_QUEUE_POLICY_ADD(preemption_timeout, PREEMPTION_TIMEOUT)
>>   MAKE_EXEC_QUEUE_POLICY_ADD(priority, SCHEDULING_PRIORITY)
>> +MAKE_EXEC_QUEUE_POLICY_ADD(slpc_exec_queue_freq_req, SLPM_GT_FREQUENCY)
>>   #undef MAKE_EXEC_QUEUE_POLICY_ADD
>>   
>>   static const int xe_exec_queue_prio_to_guc[] = {
>> @@ -414,14 +416,20 @@ static void init_policies(struct xe_guc *guc, struct xe_exec_queue *q)
>>   	struct exec_queue_policy policy;
>>   	enum xe_exec_queue_priority prio = q->sched_props.priority;
>>   	u32 timeslice_us = q->sched_props.timeslice_us;
>> +	u32 slpc_exec_queue_freq_req = 0;
>>   	u32 preempt_timeout_us = q->sched_props.preempt_timeout_us;
>>   
>>   	xe_gt_assert(guc_to_gt(guc), exec_queue_registered(q));
>>   
>> +	if (q->flags & EXEC_QUEUE_FLAG_LOW_LATENCY)
>> +		slpc_exec_queue_freq_req |= SLPC_EXEC_QUEUE_FREQ_REQ_IS_COMPUTE;
>> +
>>   	__guc_exec_queue_policy_start_klv(&policy, q->guc->id);
>>   	__guc_exec_queue_policy_add_priority(&policy, xe_exec_queue_prio_to_guc[prio]);
>>   	__guc_exec_queue_policy_add_execution_quantum(&policy, timeslice_us);
>>   	__guc_exec_queue_policy_add_preemption_timeout(&policy, preempt_timeout_us);
>> +	__guc_exec_queue_policy_add_slpc_exec_queue_freq_req(&policy,
>> +							     slpc_exec_queue_freq_req);
>>   
>>   	xe_guc_ct_send(&guc->ct, (u32 *)&policy.h2g,
>>   		       __guc_exec_queue_policy_action_size(&policy), 0, 0);
>> diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
>> index c059639613f7..136280c0c6b9 100644
>> --- a/drivers/gpu/drm/xe/xe_query.c
>> +++ b/drivers/gpu/drm/xe/xe_query.c
>> @@ -334,7 +334,8 @@ static int query_config(struct xe_device *xe, struct drm_xe_device_query *query)
>>   		xe->info.devid | (xe->info.revid << 16);
>>   	if (xe_device_get_root_tile(xe)->mem.vram.usable_size)
>>   		config->info[DRM_XE_QUERY_CONFIG_FLAGS] =
>> -			DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM;
>> +			DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM |
>> +			DRM_XE_QUERY_CONFIG_FLAG_HAS_LOW_LATENCY;
>>   	config->info[DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT] =
>>   		xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K ? SZ_64K : SZ_4K;
>>   	config->info[DRM_XE_QUERY_CONFIG_VA_BITS] = xe->info.va_bits;
>> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
>> index cac607a30f6d..1abad0c6e242 100644
>> --- a/include/uapi/drm/xe_drm.h
>> +++ b/include/uapi/drm/xe_drm.h
>> @@ -393,6 +393,8 @@ struct drm_xe_query_mem_regions {
>>    *
>>    *    - %DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM - Flag is set if the device
>>    *      has usable VRAM
>> + *    - %DRM_XE_QUERY_CONFIG_FLAG_HAS_LOW_LATENCY - Flag is set if the device
>> + *      has low latency hint support
>>    *  - %DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT - Minimal memory alignment
>>    *    required by this device, typically SZ_4K or SZ_64K
>>    *  - %DRM_XE_QUERY_CONFIG_VA_BITS - Maximum bits of a virtual address
>> @@ -409,6 +411,7 @@ struct drm_xe_query_config {
>>   #define DRM_XE_QUERY_CONFIG_REV_AND_DEVICE_ID	0
>>   #define DRM_XE_QUERY_CONFIG_FLAGS			1
>>   	#define DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM	(1 << 0)
>> +	#define DRM_XE_QUERY_CONFIG_FLAG_HAS_LOW_LATENCY	(1 << 1)
>>   #define DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT		2
>>   #define DRM_XE_QUERY_CONFIG_VA_BITS			3
>>   #define DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY	4
>> @@ -1124,6 +1127,7 @@ struct drm_xe_vm_bind {
>>    *         .engine_class = DRM_XE_ENGINE_CLASS_RENDER,
>>    *     };
>>    *     struct drm_xe_exec_queue_create exec_queue_create = {
>> + *          .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT or 0
>>    *          .extensions = 0,
>>    *          .vm_id = vm,
>>    *          .num_bb_per_exec = 1,
>> @@ -1150,7 +1154,8 @@ struct drm_xe_exec_queue_create {
>>   	/** @vm_id: VM to use for this exec queue */
>>   	__u32 vm_id;
>>   
>> -	/** @flags: MBZ */
>> +#define DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT	(1 << 0)
>> +	/** @flags: flags to use for this exec queue */
>>   	__u32 flags;
>>   
>>   	/** @exec_queue_id: Returned exec queue ID */
>> -- 
>> 2.43.0
>>


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