[PATCH V8] drm/xe/uapi: Use hint for guc to set GT frequency
Mrozek, Michal
michal.mrozek at intel.com
Mon Feb 17 10:25:16 UTC 2025
>> 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 Compute PR : https://github.com/intel/compute-runtime/pull/794
>> UMD Mesa PR : https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33214
>>
>> v8(Vinay):
>> - Add separate example for using low latency hint
>> v7(Jose):
>> - Update UMD PR
>> - applicable to all gpus
>> V6:
>> - init flags, remove redundant flags check (MAuld)
>> V5:
>> - Move uapi doc to documentation and GuC ABI specific change (Rodrigo)
>> - Modify logic to restrict exec queue flags (MAuld)
>> 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>
>> ---
>> Documentation/gpu/drm-uapi.rst | 18 ++++++++++++++++
>> drivers/gpu/drm/xe/abi/guc_actions_slpc_abi.h | 3 +++
>> drivers/gpu/drm/xe/xe_exec_queue.c | 10 ++++++---
>> drivers/gpu/drm/xe/xe_exec_queue_types.h | 2 ++
>> 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 | 2 ++
>> include/uapi/drm/xe_drm.h | 21 ++++++++++++++++++-
>> 8 files changed, 76 insertions(+), 4 deletions(-)
>>
>> diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst index b75cc9a70d1f..234c38ef26e3 100644
>> --- a/Documentation/gpu/drm-uapi.rst
>> +++ b/Documentation/gpu/drm-uapi.rst
>> @@ -583,3 +583,21 @@ dma-buf interoperability
>>
>> Please see Documentation/userspace-api/dma-buf-alloc-exchange.rst for information on how dma-buf is integrated and exposed within DRM.
>> +
>> +Low latency hint by user
>> +========================
>> +
>> +Allow users to provide a hint to kernel for cases demanding low latency profile.
>> +
>> +user need to indicate low latency hint with flag while creating exec
>> +queue as mentioned below,
>> +
>> + struct drm_xe_exec_queue_create exec_queue_create = {
>> + .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT
>> + .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);
>> 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..b28c8fa061f7 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_CTX_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 6051db78d706..f68b597f5270 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
>> @@ -605,11 +605,12 @@ int xe_exec_queue_create_ioctl(struct drm_device *dev, void *data,
>> struct xe_tile *tile;
>> struct xe_exec_queue *q = NULL;
>> u32 logical_mask;
>> + u32 flags = 0;
>> u32 id;
>> u32 len;
>> int err;
>>
>> - if (XE_IOCTL_DBG(xe, args->flags) ||
>> + if (XE_IOCTL_DBG(xe, args->flags &
>> +~DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT) ||
>> XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
>> return -EINVAL;
>>
>> @@ -626,6 +627,9 @@ 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) || @@ -634,8 +638,8 @@ 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;
>>
>> @@ -682,7 +686,7 @@ 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 6eb7ff091534..cc1cffb5c87f 100644
>> --- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> +++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
>> @@ -85,6 +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 diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c index 02409eedb914..25040efa043f 100644
>> --- a/drivers/gpu/drm/xe/xe_guc_pc.c
>> +++ b/drivers/gpu/drm/xe/xe_guc_pc.c
>> @@ -995,6 +995,17 @@ static int pc_init_freqs(struct xe_guc_pc *pc)
>> return ret;
>> }
>>
>> +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
>> @@ -1054,6 +1065,11 @@ 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..f2ce3086838c 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_CTX_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 042f87a688e7..102923d3dc74 100644
>> --- a/drivers/gpu/drm/xe/xe_query.c
>> +++ b/drivers/gpu/drm/xe/xe_query.c
>> @@ -336,6 +336,8 @@ static int query_config(struct xe_device *xe, struct drm_xe_device_query *query)
>> 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;
>> + config->info[DRM_XE_QUERY_CONFIG_FLAGS] |=
>> + 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 892f54d3aa09..7f8a51fa54a3 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
>> @@ -1204,6 +1207,21 @@ struct drm_xe_vm_bind {
>> * };
>> * ioctl(fd, DRM_IOCTL_XE_EXEC_QUEUE_CREATE, &exec_queue_create);
>> *
>> + * Allow users to provide a hint to kernel for cases demanding low latency profile.
>> +
>> + * user need to indicate low latency hint with flag while creating exec queue
>> + * as mentioned below,
>> + *
>> + * struct drm_xe_exec_queue_create exec_queue_create = {
>> + * .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT
>> + * .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);
>> + *
>> */
>> struct drm_xe_exec_queue_create {
>> #define DRM_XE_EXEC_QUEUE_EXTENSION_SET_PROPERTY 0
>> @@ -1222,7 +1240,8 @@ 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
Acked-by: Michal Mrozek <michal.mrozek at intel.com>
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