[PATCH libdrm] amdgpu: add a faster BO list API

Christian König ckoenig.leichtzumerken at gmail.com
Wed Jan 16 12:55:00 UTC 2019


Well if you ask me we should have the following interface for 
negotiating memory management with the kernel:

1. We have per process BOs which can't be shared between processes.

Those are always valid and don't need to be mentioned in any BO list 
whatsoever.

If we knew that a per process BO is currently not in use we can 
optionally tell that to the kernel to make memory management more efficient.

In other words instead of a list of stuff which is used we send down to 
the kernel a list of stuff which is not used any more and that only when 
we know that it is necessary, e.g. when a game or application overcommits.

2. We have shared BOs which are used by more than one process.

Those are rare and should be added to the per CS list of BOs in use.


The whole BO list interface Marek tries to optimize here should be 
deprecated and not used any more.

Regards,
Christian.

Am 16.01.19 um 13:46 schrieb Bas Nieuwenhuizen:
> So random questions:
>
> 1) In this discussion it was mentioned that some Vulkan drivers still
> use the bo_list interface. I think that implies radv as I think we're
> still using bo_list. Is there any other API we should be using? (Also,
> with VK_EXT_descriptor_indexing I suspect we'll be moving more towards
> a global bo list instead of a cmd buffer one, as we cannot know all
> the BOs referenced anymore, but not sure what end state here will be).
>
> 2) The other alternative mentioned was adding the buffers directly
> into the submit ioctl. Is this the desired end state (though as above
> I'm not sure how that works for vulkan)? If yes, what is the timeline
> for this that we need something in the interim?
>
> 3) Did we measure any performance benefit?
>
> In general I'd like to to ack the raw bo list creation function as
> this interface seems easier to use. The two arrays thing has always
> been kind of a pain when we want to use e.g. builtin sort functions to
> make sure we have no duplicate BOs, but have some comments below.
>
> On Mon, Jan 7, 2019 at 8:31 PM Marek Olšák <maraeo at gmail.com> wrote:
>> From: Marek Olšák <marek.olsak at amd.com>
>>
>> ---
>>   amdgpu/amdgpu-symbol-check |  3 ++
>>   amdgpu/amdgpu.h            | 56 +++++++++++++++++++++++++++++++++++++-
>>   amdgpu/amdgpu_bo.c         | 36 ++++++++++++++++++++++++
>>   amdgpu/amdgpu_cs.c         | 25 +++++++++++++++++
>>   4 files changed, 119 insertions(+), 1 deletion(-)
>>
>> diff --git a/amdgpu/amdgpu-symbol-check b/amdgpu/amdgpu-symbol-check
>> index 6f5e0f95..96a44b40 100755
>> --- a/amdgpu/amdgpu-symbol-check
>> +++ b/amdgpu/amdgpu-symbol-check
>> @@ -12,20 +12,22 @@ _edata
>>   _end
>>   _fini
>>   _init
>>   amdgpu_bo_alloc
>>   amdgpu_bo_cpu_map
>>   amdgpu_bo_cpu_unmap
>>   amdgpu_bo_export
>>   amdgpu_bo_free
>>   amdgpu_bo_import
>>   amdgpu_bo_inc_ref
>> +amdgpu_bo_list_create_raw
>> +amdgpu_bo_list_destroy_raw
>>   amdgpu_bo_list_create
>>   amdgpu_bo_list_destroy
>>   amdgpu_bo_list_update
>>   amdgpu_bo_query_info
>>   amdgpu_bo_set_metadata
>>   amdgpu_bo_va_op
>>   amdgpu_bo_va_op_raw
>>   amdgpu_bo_wait_for_idle
>>   amdgpu_create_bo_from_user_mem
>>   amdgpu_cs_chunk_fence_info_to_data
>> @@ -40,20 +42,21 @@ amdgpu_cs_destroy_semaphore
>>   amdgpu_cs_destroy_syncobj
>>   amdgpu_cs_export_syncobj
>>   amdgpu_cs_fence_to_handle
>>   amdgpu_cs_import_syncobj
>>   amdgpu_cs_query_fence_status
>>   amdgpu_cs_query_reset_state
>>   amdgpu_query_sw_info
>>   amdgpu_cs_signal_semaphore
>>   amdgpu_cs_submit
>>   amdgpu_cs_submit_raw
>> +amdgpu_cs_submit_raw2
>>   amdgpu_cs_syncobj_export_sync_file
>>   amdgpu_cs_syncobj_import_sync_file
>>   amdgpu_cs_syncobj_reset
>>   amdgpu_cs_syncobj_signal
>>   amdgpu_cs_syncobj_wait
>>   amdgpu_cs_wait_fences
>>   amdgpu_cs_wait_semaphore
>>   amdgpu_device_deinitialize
>>   amdgpu_device_initialize
>>   amdgpu_find_bo_by_cpu_mapping
>> diff --git a/amdgpu/amdgpu.h b/amdgpu/amdgpu.h
>> index dc51659a..5b800033 100644
>> --- a/amdgpu/amdgpu.h
>> +++ b/amdgpu/amdgpu.h
>> @@ -35,20 +35,21 @@
>>   #define _AMDGPU_H_
>>
>>   #include <stdint.h>
>>   #include <stdbool.h>
>>
>>   #ifdef __cplusplus
>>   extern "C" {
>>   #endif
>>
>>   struct drm_amdgpu_info_hw_ip;
>> +struct drm_amdgpu_bo_list_entry;
>>
>>   /*--------------------------------------------------------------------------*/
>>   /* --------------------------- Defines ------------------------------------ */
>>   /*--------------------------------------------------------------------------*/
>>
>>   /**
>>    * Define max. number of Command Buffers (IB) which could be sent to the single
>>    * hardware IP to accommodate CE/DE requirements
>>    *
>>    * \sa amdgpu_cs_ib_info
>> @@ -767,34 +768,65 @@ int amdgpu_bo_cpu_unmap(amdgpu_bo_handle buf_handle);
>>    *                            and no GPU access is scheduled.
>>    *                          1 GPU access is in fly or scheduled
>>    *
>>    * \return   0 - on success
>>    *          <0 - Negative POSIX Error code
>>    */
>>   int amdgpu_bo_wait_for_idle(amdgpu_bo_handle buf_handle,
>>                              uint64_t timeout_ns,
>>                              bool *buffer_busy);
>>
>> +/**
>> + * Creates a BO list handle for command submission.
>> + *
>> + * \param   dev                        - \c [in] Device handle.
>> + *                                See #amdgpu_device_initialize()
>> + * \param   number_of_buffers  - \c [in] Number of BOs in the list
>> + * \param   buffers            - \c [in] List of BO handles
>> + * \param   result             - \c [out] Created BO list handle
>> + *
>> + * \return   0 on success\n
>> + *          <0 - Negative POSIX Error code
>> + *
>> + * \sa amdgpu_bo_list_destroy_raw()
>> +*/
>> +int amdgpu_bo_list_create_raw(amdgpu_device_handle dev,
>> +                             uint32_t number_of_buffers,
>> +                             struct drm_amdgpu_bo_list_entry *buffers,
>> +                             uint32_t *result);
> So AFAIU  drm_amdgpu_bo_list_entry takes a raw bo handle while we
> never get a raw bo handle from libdrm_amdgpu. How are we supposed to
> fill it in?
>
> What do we win by having the raw handle for the bo_list? If we would
> not return the raw handle we would not need the submit_raw2.
>
>> +
>> +/**
>> + * Destroys a BO list handle.
>> + *
>> + * \param   bo_list    - \c [in] BO list handle.
>> + *
>> + * \return   0 on success\n
>> + *          <0 - Negative POSIX Error code
>> + *
>> + * \sa amdgpu_bo_list_create_raw(), amdgpu_cs_submit_raw2()
>> +*/
>> +int amdgpu_bo_list_destroy_raw(amdgpu_device_handle dev, uint32_t bo_list);
>> +
>>   /**
>>    * Creates a BO list handle for command submission.
>>    *
>>    * \param   dev                        - \c [in] Device handle.
>>    *                                See #amdgpu_device_initialize()
>>    * \param   number_of_resources        - \c [in] Number of BOs in the list
>>    * \param   resources          - \c [in] List of BO handles
>>    * \param   resource_prios     - \c [in] Optional priority for each handle
>>    * \param   result             - \c [out] Created BO list handle
>>    *
>>    * \return   0 on success\n
>>    *          <0 - Negative POSIX Error code
>>    *
>> - * \sa amdgpu_bo_list_destroy()
>> + * \sa amdgpu_bo_list_destroy(), amdgpu_cs_submit_raw2()
>>   */
>>   int amdgpu_bo_list_create(amdgpu_device_handle dev,
>>                            uint32_t number_of_resources,
>>                            amdgpu_bo_handle *resources,
>>                            uint8_t *resource_prios,
>>                            amdgpu_bo_list_handle *result);
>>
>>   /**
>>    * Destroys a BO list handle.
>>    *
>> @@ -1580,20 +1612,42 @@ struct drm_amdgpu_cs_chunk;
>>   struct drm_amdgpu_cs_chunk_dep;
>>   struct drm_amdgpu_cs_chunk_data;
>>
>>   int amdgpu_cs_submit_raw(amdgpu_device_handle dev,
>>                           amdgpu_context_handle context,
>>                           amdgpu_bo_list_handle bo_list_handle,
>>                           int num_chunks,
>>                           struct drm_amdgpu_cs_chunk *chunks,
>>                           uint64_t *seq_no);
>>
>> +/**
>> + * Submit raw command submission to the kernel with a raw BO list handle.
>> + *
>> + * \param   dev               - \c [in] device handle
>> + * \param   context    - \c [in] context handle for context id
>> + * \param   bo_list_handle - \c [in] raw bo list handle (0 for none)
>> + * \param   num_chunks - \c [in] number of CS chunks to submit
>> + * \param   chunks     - \c [in] array of CS chunks
>> + * \param   seq_no     - \c [out] output sequence number for submission.
>> + *
>> + * \return   0 on success\n
>> + *          <0 - Negative POSIX Error code
>> + *
>> + * \sa amdgpu_bo_list_create_raw(), amdgpu_bo_list_destroy_raw()
>> + */
>> +int amdgpu_cs_submit_raw2(amdgpu_device_handle dev,
>> +                         amdgpu_context_handle context,
>> +                         uint32_t bo_list_handle,
>> +                         int num_chunks,
>> +                         struct drm_amdgpu_cs_chunk *chunks,
>> +                         uint64_t *seq_no);
>> +
>>   void amdgpu_cs_chunk_fence_to_dep(struct amdgpu_cs_fence *fence,
>>                                    struct drm_amdgpu_cs_chunk_dep *dep);
>>   void amdgpu_cs_chunk_fence_info_to_data(struct amdgpu_cs_fence_info *fence_info,
>>                                          struct drm_amdgpu_cs_chunk_data *data);
>>
>>   /**
>>    * Reserve VMID
>>    * \param   context - \c [in]  GPU Context
>>    * \param   flags - \c [in]  TBD
>>    *
>> diff --git a/amdgpu/amdgpu_bo.c b/amdgpu/amdgpu_bo.c
>> index c0f42e81..21bc73aa 100644
>> --- a/amdgpu/amdgpu_bo.c
>> +++ b/amdgpu/amdgpu_bo.c
>> @@ -611,20 +611,56 @@ drm_public int amdgpu_create_bo_from_user_mem(amdgpu_device_handle dev,
>>          pthread_mutex_lock(&dev->bo_table_mutex);
>>          r = handle_table_insert(&dev->bo_handles, (*buf_handle)->handle,
>>                                  *buf_handle);
>>          pthread_mutex_unlock(&dev->bo_table_mutex);
>>          if (r)
>>                  amdgpu_bo_free(*buf_handle);
>>   out:
>>          return r;
>>   }
>>
>> +drm_public int amdgpu_bo_list_create_raw(amdgpu_device_handle dev,
>> +                                        uint32_t number_of_buffers,
>> +                                        struct drm_amdgpu_bo_list_entry *buffers,
>> +                                        uint32_t *result)
>> +{
>> +       union drm_amdgpu_bo_list args;
>> +       int r;
>> +
>> +       memset(&args, 0, sizeof(args));
>> +       args.in.operation = AMDGPU_BO_LIST_OP_CREATE;
>> +       args.in.bo_number = number_of_buffers;
>> +       args.in.bo_info_size = sizeof(struct drm_amdgpu_bo_list_entry);
>> +       args.in.bo_info_ptr = (uint64_t)(uintptr_t)buffers;
>> +
>> +       r = drmCommandWriteRead(dev->fd, DRM_AMDGPU_BO_LIST,
>> +                               &args, sizeof(args));
>> +       if (r)
>> +               return r;
>> +
>> +       *result = args.out.list_handle;
>> +       return 0;
>> +}
>> +
>> +drm_public int amdgpu_bo_list_destroy_raw(amdgpu_device_handle dev,
>> +                                         uint32_t bo_list)
>> +{
>> +       union drm_amdgpu_bo_list args;
>> +
>> +       memset(&args, 0, sizeof(args));
>> +       args.in.operation = AMDGPU_BO_LIST_OP_DESTROY;
>> +       args.in.list_handle = bo_list;
>> +
>> +       return drmCommandWriteRead(dev->fd, DRM_AMDGPU_BO_LIST,
>> +                                  &args, sizeof(args));
>> +}
>> +
>>   drm_public int amdgpu_bo_list_create(amdgpu_device_handle dev,
>>                                       uint32_t number_of_resources,
>>                                       amdgpu_bo_handle *resources,
>>                                       uint8_t *resource_prios,
>>                                       amdgpu_bo_list_handle *result)
>>   {
>>          struct drm_amdgpu_bo_list_entry *list;
>>          union drm_amdgpu_bo_list args;
>>          unsigned i;
>>          int r;
>> diff --git a/amdgpu/amdgpu_cs.c b/amdgpu/amdgpu_cs.c
>> index 3b8231aa..5bedf748 100644
>> --- a/amdgpu/amdgpu_cs.c
>> +++ b/amdgpu/amdgpu_cs.c
>> @@ -724,20 +724,45 @@ drm_public int amdgpu_cs_submit_raw(amdgpu_device_handle dev,
>>          r = drmCommandWriteRead(dev->fd, DRM_AMDGPU_CS,
>>                                  &cs, sizeof(cs));
>>          if (r)
>>                  return r;
>>
>>          if (seq_no)
>>                  *seq_no = cs.out.handle;
>>          return 0;
>>   }
>>
>> +drm_public int amdgpu_cs_submit_raw2(amdgpu_device_handle dev,
>> +                                    amdgpu_context_handle context,
>> +                                    uint32_t bo_list_handle,
>> +                                    int num_chunks,
>> +                                    struct drm_amdgpu_cs_chunk *chunks,
>> +                                    uint64_t *seq_no)
>> +{
>> +       union drm_amdgpu_cs cs = {0};
>> +       uint64_t *chunk_array;
>> +       int i, r;
>> +
>> +       chunk_array = alloca(sizeof(uint64_t) * num_chunks);
>> +       for (i = 0; i < num_chunks; i++)
>> +               chunk_array[i] = (uint64_t)(uintptr_t)&chunks[i];
>> +       cs.in.chunks = (uint64_t)(uintptr_t)chunk_array;
>> +       cs.in.ctx_id = context->id;
>> +       cs.in.bo_list_handle = bo_list_handle;
>> +       cs.in.num_chunks = num_chunks;
>> +       r = drmCommandWriteRead(dev->fd, DRM_AMDGPU_CS,
>> +                               &cs, sizeof(cs));
>> +       if (!r && seq_no)
>> +               *seq_no = cs.out.handle;
>> +       return r;
>> +}
>> +
>>   drm_public void amdgpu_cs_chunk_fence_info_to_data(struct amdgpu_cs_fence_info *fence_info,
>>                                          struct drm_amdgpu_cs_chunk_data *data)
>>   {
>>          data->fence_data.handle = fence_info->handle->handle;
>>          data->fence_data.offset = fence_info->offset * sizeof(uint64_t);
>>   }
>>
>>   drm_public void amdgpu_cs_chunk_fence_to_dep(struct amdgpu_cs_fence *fence,
>>                                          struct drm_amdgpu_cs_chunk_dep *dep)
>>   {
>> --
>> 2.17.1
>>
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