[PATCH V8] drm/xe/uapi: Use hint for guc to set GT frequency
Upadhyay, Tejas
tejas.upadhyay at intel.com
Sat Feb 22 07:06:17 UTC 2025
> -----Original Message-----
> From: Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Sent: Friday, February 21, 2025 11:46 PM
> To: Belgaumkar, Vinay <vinay.belgaumkar at intel.com>
> Cc: Upadhyay, Tejas <tejas.upadhyay at intel.com>; intel-
> xe at lists.freedesktop.org; Mrozek, Michal <michal.mrozek at intel.com>;
> Morek, Szymon <szymon.morek at intel.com>; Souza, Jose
> <jose.souza at intel.com>; Auld, Matthew <matthew.auld at intel.com>
> Subject: Re: [PATCH V8] drm/xe/uapi: Use hint for guc to set GT frequency
>
> On Tue, Feb 11, 2025 at 11:16:50AM -0800, Belgaumkar, Vinay wrote:
> >
> > On 2/6/2025 10:12 PM, 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.
> > nit: realign this line length, seems to be longer than others in the
> > commit message.
> > > 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.
> > > +
> > nit: extra line.
> > > +user need to indicate low latency hint with flag while creating
> > > +exec queue
> > s/user need to/User can/ - this was in the last review as well. Might
> > be good to indicate that this will affect power consumption.
> > > +as mentioned below,
> > > +
> > > + struct drm_xe_exec_queue_create exec_queue_create = {
> > > + .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT
> > missing "," at eol
> > > + .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.
> > > +
> > same issues as above, extra line
> > > + * user need to indicate low latency hint with flag while creating exec
> queue
> > s/user need to/User can
> > > + * as mentioned below,
> > > + *
> > > + * struct drm_xe_exec_queue_create exec_queue_create = {
> > > + * .flags = DRM_XE_EXEC_QUEUE_LOW_LATENCY_HINT
> > missing "," at eol
> > > + * .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;
> >
> > With above minor cosmetic issues fixed, this is
>
> Any v9 coming soon? It looks we don't have further concerns with this and we
> could get this in soon...
Hi, It is on patchwork already, https://patchwork.freedesktop.org/patch/636620/ .
Tejas
>
> >
> > Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
> >
> > > /** @exec_queue_id: Returned exec queue ID */
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