[RFC PATCH V2] drm/xe/guc: Use exec queue hints for GT frequency
Belgaumkar, Vinay
vinay.belgaumkar at intel.com
Thu Jan 9 18:36:52 UTC 2025
On 1/9/2025 6:36 AM, Souza, Jose wrote:
> On Thu, 2025-01-09 at 17:37 +0530, Tejas Upadhyay wrote:
>> Allow user to provide a low latency hint per exec queue. When set,
>> KMD sends a hint to GuC which results in special handling for this
>> exec queue. SLPC will ramp the GT frequency aggressively every time
>> it switches to this exec queue.
Clearer to say context instead of exec queue.
>>
>> We need to enable the use of SLPC Compute strategy during init, but
>> it will apply only to exec queues that set this bit during exec queue
>> 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
>> * .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);
>>
>> Link to UMD PR : https://github.com/intel/compute-runtime/pull/794
>>
>> Note: There is outstanding issue on guc side to be not able to switch to max
>> frequency as per strategy indicated by KMD, so for experminet/test result
>> hardcoding apporch was taken and passed to guc as policy. Effort on debugging
>> from guc side is going on in parallel.
I verified this works fine. Seems like there was some issue with an
older GuC version.
>>
>> V2:
>> - DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT 1 is already planned for other hint(Szymon)
>> - Add motivation to description (Lucas)
>>
>> Cc:dri-devel at lists.freedesktop.org
>> Cc:vinay.belgaumkar at intel.com
>> Cc:Michal Mrozek <michal.mrozek at intel.com>
>> Cc:Szymon Morek <szymon.morek at intel.com>
>> Cc:José Roberto de Souza <jose.souza at intel.com>
>> 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 | 7 ++++---
>> drivers/gpu/drm/xe/xe_guc_pc.c | 16 ++++++++++++++++
>> drivers/gpu/drm/xe/xe_guc_submit.c | 7 +++++++
>> include/uapi/drm/xe_drm.h | 3 ++-
>> 5 files changed, 32 insertions(+), 4 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)
>> +#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..7747ba6c4bb8 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>> @@ -553,7 +553,8 @@ 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)) ||
As mentioned in the comments, we need flags separate for external API
and internally. i915 implementation has this -
https://patchwork.freedesktop.org/series/130698/.
>> XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
>> return -EINVAL;
>>
>> @@ -578,7 +579,7 @@ 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;
>> + u32 flags = args->flags | EXEC_QUEUE_FLAG_VM;
>>
>> if (id)
>> flags |= EXEC_QUEUE_FLAG_BIND_ENGINE_CHILD;
>> @@ -626,7 +627,7 @@ 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, args->flags,
>> args->extensions);
>> up_read(&vm->lock);
>> xe_vm_put(vm);
>> diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
>> index df7f130fb663..ff0b98ccf1a7 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
>> @@ -992,6 +992,19 @@ static int pc_init_freqs(struct xe_guc_pc *pc)
>> return ret;
>> }
>>
>> +static int xe_guc_pc_set_strategy(struct xe_guc_pc *pc, u32 val)
>> +{
>> + int ret = 0;
>> +
>> + xe_pm_runtime_get(pc_to_xe(pc));
We are already holding fwake from caller, no need to get runtime ref.
Maybe just assert if we don't have it?
>> + ret = pc_action_set_param(pc,
>> + SLPC_PARAM_STRATEGIES,
>> + val);
>> + xe_pm_runtime_put(pc_to_xe(pc));
>> +
>> + return ret;
>> +}
>> +
>> /**
>> * xe_guc_pc_start - Start GuC's Power Conservation component
>> * @pc: Xe_GuC_PC instance
>> @@ -1052,6 +1065,9 @@ int xe_guc_pc_start(struct xe_guc_pc *pc)
>>
>> ret = pc_action_setup_gucrc(pc, GUCRC_FIRMWARE_CONTROL);
>>
>> + /* Enable SLPC Optimized Strategy for compute */
>> + xe_guc_pc_set_strategy(pc, SLPC_OPTIMIZED_STRATEGY_COMPUTE);
better to check the ret here.
>> +
>> out:
>> xe_force_wake_put(gt_to_fw(gt), fw_ref);
>> return ret;
>> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
>> index 9c36329fe857..88a1987ac360 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_ctx_freq_req, SLPM_GT_FREQUENCY)
>> #undef MAKE_EXEC_QUEUE_POLICY_ADD
>>
>> static const int xe_exec_queue_prio_to_guc[] = {
>> @@ -414,14 +416,19 @@ 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_ctx_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 & DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT)
>> + slpc_ctx_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_ctx_freq_req(&policy, slpc_ctx_freq_req);
>>
>> xe_guc_ct_send(&guc->ct, (u32 *)&policy.h2g,
>> __guc_exec_queue_policy_action_size(&policy), 0, 0);
>> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
>> index f62689ca861a..bd0150d2200c 100644
>> --- a/include/uapi/drm/xe_drm.h
>> +++ b/include/uapi/drm/xe_drm.h
>> @@ -1097,6 +1097,7 @@ 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,
>> @@ -1110,7 +1111,6 @@ struct drm_xe_exec_queue_create {
>> #define DRM_XE_EXEC_QUEUE_EXTENSION_SET_PROPERTY 0
>> #define DRM_XE_EXEC_QUEUE_SET_PROPERTY_PRIORITY 0
>> #define DRM_XE_EXEC_QUEUE_SET_PROPERTY_TIMESLICE 1
>> -
>> /** @extensions: Pointer to the first extension struct, if any */
>> __u64 extensions;
>>
>> @@ -1123,6 +1123,7 @@ struct drm_xe_exec_queue_create {
>> /** @vm_id: VM to use for this exec queue */
>> __u32 vm_id;
>>
>> +#define DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT (0x1 << 1)
> we need a way to know if the KMD version running supports it or not.
> I think a bit on drm_xe_query_config would do the job.
Yes, the i915 implementation has this -
https://patchwork.freedesktop.org/series/130698/. We need something
similar here.
Thanks,
Vinay.
>
>> /** @flags: MBZ */
>> __u32 flags;
>>
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