[Mesa-stable] [PATCH] radv/winsys: allow to submit up to 4 IBs for chips without chaining

Samuel Pitoiset samuel.pitoiset at gmail.com
Tue Apr 24 09:32:11 UTC 2018



On 04/24/2018 11:29 AM, Juan A. Suarez Romero wrote:
> On Tue, 2018-04-24 at 10:33 +0200, Samuel Pitoiset wrote:
>> The SI family doesn't support chaining which means the maximum
>> size in dwords per CS is limited. When that limit was reached
>> we failed to submit the CS and the application crashed.
>>
>> This patch allows to submit up to 4 IBs which is currently the
>> limit, but recent amdgpu supports more than that.
>>
>> Please note that we can reach the limit of 4 IBs per submit
>> but currently we can't improve that. The only solution is to
>> upgrade libdrm. That will be improved later but for now this
>> should fix crashes on SI or when using RADV_DEBUG=noibs.
>>
>> Fixes: 36cb5508e89 ("radv/winsys: Fail early on overgrown cs.")
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105775
>> Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
> 
> 
> I guess this requires an explicit R-b, right? Anyone?

Yeah, I think so. Bas will reply later today I guess.

> 
> 	J.A.
> 
>> ---
>>   src/amd/vulkan/winsys/amdgpu/radv_amdgpu_cs.c | 219 ++++++++++++++----
>>   1 file changed, 169 insertions(+), 50 deletions(-)
>>
>> diff --git a/src/amd/vulkan/winsys/amdgpu/radv_amdgpu_cs.c b/src/amd/vulkan/winsys/amdgpu/radv_amdgpu_cs.c
>> index 5632b1d4ee2..4195865a85d 100644
>> --- a/src/amd/vulkan/winsys/amdgpu/radv_amdgpu_cs.c
>> +++ b/src/amd/vulkan/winsys/amdgpu/radv_amdgpu_cs.c
>> @@ -66,6 +66,10 @@ struct radv_amdgpu_cs {
>>   	struct radeon_winsys_bo     **virtual_buffers;
>>   	uint8_t                     *virtual_buffer_priorities;
>>   	int                         *virtual_buffer_hash_table;
>> +
>> +	/* For chips that don't support chaining. */
>> +	struct radeon_winsys_cs     *old_cs_buffers;
>> +	unsigned                    num_old_cs_buffers;
>>   };
>>   
>>   static inline struct radv_amdgpu_cs *
>> @@ -166,6 +170,12 @@ static void radv_amdgpu_cs_destroy(struct radeon_winsys_cs *rcs)
>>   	for (unsigned i = 0; i < cs->num_old_ib_buffers; ++i)
>>   		cs->ws->base.buffer_destroy(cs->old_ib_buffers[i]);
>>   
>> +	for (unsigned i = 0; i < cs->num_old_cs_buffers; ++i) {
>> +		struct radeon_winsys_cs *rcs = &cs->old_cs_buffers[i];
>> +		free(rcs->buf);
>> +	}
>> +
>> +	free(cs->old_cs_buffers);
>>   	free(cs->old_ib_buffers);
>>   	free(cs->virtual_buffers);
>>   	free(cs->virtual_buffer_priorities);
>> @@ -251,9 +261,46 @@ static void radv_amdgpu_cs_grow(struct radeon_winsys_cs *_cs, size_t min_size)
>>   		/* The total ib size cannot exceed limit_dws dwords. */
>>   		if (ib_dws > limit_dws)
>>   		{
>> -			cs->failed = true;
>> +			/* The maximum size in dwords has been reached,
>> +			 * try to allocate a new one.
>> +			 */
>> +			if (cs->num_old_cs_buffers + 1 >= AMDGPU_CS_MAX_IBS_PER_SUBMIT) {
>> +				/* TODO: Allow to submit more than 4 IBs. */
>> +				fprintf(stderr, "amdgpu: Maximum number of IBs "
>> +						"per submit reached.\n");
>> +				cs->failed = true;
>> +				cs->base.cdw = 0;
>> +				return;
>> +			}
>> +
>> +			cs->old_cs_buffers =
>> +				realloc(cs->old_cs_buffers,
>> +				        (cs->num_old_cs_buffers + 1) * sizeof(*cs->old_cs_buffers));
>> +			if (!cs->old_cs_buffers) {
>> +				cs->failed = true;
>> +				cs->base.cdw = 0;
>> +				return;
>> +			}
>> +
>> +			/* Store the current one for submitting it later. */
>> +			cs->old_cs_buffers[cs->num_old_cs_buffers].cdw = cs->base.cdw;
>> +			cs->old_cs_buffers[cs->num_old_cs_buffers].max_dw = cs->base.max_dw;
>> +			cs->old_cs_buffers[cs->num_old_cs_buffers].buf = cs->base.buf;
>> +			cs->num_old_cs_buffers++;
>> +
>> +			/* Reset the cs, it will be re-allocated below. */
>>   			cs->base.cdw = 0;
>> -			return;
>> +			cs->base.buf = NULL;
>> +
>> +			/* Re-compute the number of dwords to allocate. */
>> +			ib_dws = MAX2(cs->base.cdw + min_size,
>> +				      MIN2(cs->base.max_dw * 2, limit_dws));
>> +			if (ib_dws > limit_dws) {
>> +				fprintf(stderr, "amdgpu: Too high number of "
>> +						"dwords to allocate\n");
>> +				cs->failed = true;
>> +				return;
>> +			}
>>   		}
>>   
>>   		uint32_t *new_buf = realloc(cs->base.buf, ib_dws * 4);
>> @@ -365,6 +412,15 @@ static void radv_amdgpu_cs_reset(struct radeon_winsys_cs *_cs)
>>   		cs->ib.ib_mc_address = radv_amdgpu_winsys_bo(cs->ib_buffer)->base.va;
>>   		cs->ib_size_ptr = &cs->ib.size;
>>   		cs->ib.size = 0;
>> +	} else {
>> +		for (unsigned i = 0; i < cs->num_old_cs_buffers; ++i) {
>> +			struct radeon_winsys_cs *rcs = &cs->old_cs_buffers[i];
>> +			free(rcs->buf);
>> +		}
>> +
>> +		free(cs->old_cs_buffers);
>> +		cs->old_cs_buffers = NULL;
>> +		cs->num_old_cs_buffers = 0;
>>   	}
>>   }
>>   
>> @@ -515,7 +571,8 @@ static void radv_amdgpu_cs_execute_secondary(struct radeon_winsys_cs *_parent,
>>   static int radv_amdgpu_create_bo_list(struct radv_amdgpu_winsys *ws,
>>   				      struct radeon_winsys_cs **cs_array,
>>   				      unsigned count,
>> -				      struct radv_amdgpu_winsys_bo *extra_bo,
>> +				      struct radv_amdgpu_winsys_bo **extra_bo_array,
>> +				      unsigned num_extra_bo,
>>   				      struct radeon_winsys_cs *extra_cs,
>>   				      amdgpu_bo_list_handle *bo_list)
>>   {
>> @@ -544,7 +601,7 @@ static int radv_amdgpu_create_bo_list(struct radv_amdgpu_winsys *ws,
>>   					  bo_list);
>>   		free(handles);
>>   		pthread_mutex_unlock(&ws->global_bo_list_lock);
>> -	} else if (count == 1 && !extra_bo && !extra_cs &&
>> +	} else if (count == 1 && !num_extra_bo && !extra_cs &&
>>   	           !radv_amdgpu_cs(cs_array[0])->num_virtual_buffers) {
>>   		struct radv_amdgpu_cs *cs = (struct radv_amdgpu_cs*)cs_array[0];
>>   		if (cs->num_buffers == 0) {
>> @@ -554,8 +611,8 @@ static int radv_amdgpu_create_bo_list(struct radv_amdgpu_winsys *ws,
>>   		r = amdgpu_bo_list_create(ws->dev, cs->num_buffers, cs->handles,
>>   					  cs->priorities, bo_list);
>>   	} else {
>> -		unsigned total_buffer_count = !!extra_bo;
>> -		unsigned unique_bo_count = !!extra_bo;
>> +		unsigned total_buffer_count = num_extra_bo;
>> +		unsigned unique_bo_count = num_extra_bo;
>>   		for (unsigned i = 0; i < count; ++i) {
>>   			struct radv_amdgpu_cs *cs = (struct radv_amdgpu_cs*)cs_array[i];
>>   			total_buffer_count += cs->num_buffers;
>> @@ -578,9 +635,9 @@ static int radv_amdgpu_create_bo_list(struct radv_amdgpu_winsys *ws,
>>   			return -ENOMEM;
>>   		}
>>   
>> -		if (extra_bo) {
>> -			handles[0] = extra_bo->bo;
>> -			priorities[0] = 8;
>> +		for (unsigned i = 0; i < num_extra_bo; i++) {
>> +			handles[i] = extra_bo_array[i]->bo;
>> +			priorities[i] = 8;
>>   		}
>>   
>>   		for (unsigned i = 0; i < count + !!extra_cs; ++i) {
>> @@ -710,7 +767,8 @@ static int radv_amdgpu_winsys_cs_submit_chained(struct radeon_winsys_ctx *_ctx,
>>   		}
>>   	}
>>   
>> -	r = radv_amdgpu_create_bo_list(cs0->ws, cs_array, cs_count, NULL, initial_preamble_cs, &bo_list);
>> +	r = radv_amdgpu_create_bo_list(cs0->ws, cs_array, cs_count, NULL, 0, initial_preamble_cs,
>> +	                               &bo_list);
>>   	if (r) {
>>   		fprintf(stderr, "amdgpu: buffer list creation failed for the "
>>   				"chained submission(%d)\n", r);
>> @@ -777,7 +835,7 @@ static int radv_amdgpu_winsys_cs_submit_fallback(struct radeon_winsys_ctx *_ctx,
>>   
>>   		memset(&request, 0, sizeof(request));
>>   
>> -		r = radv_amdgpu_create_bo_list(cs0->ws, &cs_array[i], cnt, NULL,
>> +		r = radv_amdgpu_create_bo_list(cs0->ws, &cs_array[i], cnt, NULL, 0,
>>   		                               preamble_cs, &bo_list);
>>   		if (r) {
>>   			fprintf(stderr, "amdgpu: buffer list creation failed "
>> @@ -857,68 +915,127 @@ static int radv_amdgpu_winsys_cs_submit_sysmem(struct radeon_winsys_ctx *_ctx,
>>   	assert(cs_count);
>>   
>>   	for (unsigned i = 0; i < cs_count;) {
>> -		struct amdgpu_cs_ib_info ib = {0};
>> -		struct radeon_winsys_bo *bo = NULL;
>> +		struct amdgpu_cs_ib_info ibs[AMDGPU_CS_MAX_IBS_PER_SUBMIT] = {0};
>> +		unsigned number_of_ibs = 1;
>> +		struct radeon_winsys_bo *bos[AMDGPU_CS_MAX_IBS_PER_SUBMIT] = {0};
>>   		struct radeon_winsys_cs *preamble_cs = i ? continue_preamble_cs : initial_preamble_cs;
>> +		struct radv_amdgpu_cs *cs = radv_amdgpu_cs(cs_array[i]);
>>   		uint32_t *ptr;
>>   		unsigned cnt = 0;
>>   		unsigned size = 0;
>>   		unsigned pad_words = 0;
>> -		if (preamble_cs)
>> -			size += preamble_cs->cdw;
>>   
>> -		while (i + cnt < cs_count && 0xffff8 - size >= radv_amdgpu_cs(cs_array[i + cnt])->base.cdw) {
>> -			size += radv_amdgpu_cs(cs_array[i + cnt])->base.cdw;
>> -			++cnt;
>> -		}
>> +		if (cs->num_old_cs_buffers > 0) {
>> +			/* Special path when the maximum size in dwords has
>> +			 * been reached because we need to handle more than one
>> +			 * IB per submit.
>> +			 */
>> +			unsigned new_cs_count = cs->num_old_cs_buffers + 1;
>> +			struct radeon_winsys_cs *new_cs_array[AMDGPU_CS_MAX_IBS_PER_SUBMIT];
>> +			unsigned idx = 0;
>> +
>> +			for (unsigned j = 0; j < cs->num_old_cs_buffers; j++)
>> +				new_cs_array[idx++] = &cs->old_cs_buffers[j];
>> +			new_cs_array[idx++] = cs_array[i];
>> +
>> +			for (unsigned j = 0; j < new_cs_count; j++) {
>> +				struct radeon_winsys_cs *rcs = new_cs_array[j];
>> +				bool needs_preamble = preamble_cs && j == 0;
>> +				unsigned size = 0;
>> +
>> +				if (needs_preamble)
>> +					size += preamble_cs->cdw;
>> +				size += rcs->cdw;
>> +
>> +				assert(size < 0xffff8);
>> +
>> +				while (!size || (size & 7)) {
>> +					size++;
>> +					pad_words++;
>> +				}
>>   
>> -		while(!size || (size & 7)) {
>> -			size++;
>> -			pad_words++;
>> -		}
>> -		assert(cnt);
>> +				bos[j] = ws->buffer_create(ws, 4 * size, 4096,
>> +							   RADEON_DOMAIN_GTT,
>> +							   RADEON_FLAG_CPU_ACCESS |
>> +							   RADEON_FLAG_NO_INTERPROCESS_SHARING |
>> +							   RADEON_FLAG_READ_ONLY);
>> +				ptr = ws->buffer_map(bos[j]);
>>   
>> -		bo = ws->buffer_create(ws, 4 * size, 4096, RADEON_DOMAIN_GTT,
>> -				       RADEON_FLAG_CPU_ACCESS |
>> -				       RADEON_FLAG_NO_INTERPROCESS_SHARING |
>> -				       RADEON_FLAG_READ_ONLY);
>> -		ptr = ws->buffer_map(bo);
>> +				if (needs_preamble) {
>> +					memcpy(ptr, preamble_cs->buf, preamble_cs->cdw * 4);
>> +					ptr += preamble_cs->cdw;
>> +				}
>>   
>> -		if (preamble_cs) {
>> -			memcpy(ptr, preamble_cs->buf, preamble_cs->cdw * 4);
>> -			ptr += preamble_cs->cdw;
>> -		}
>> +				memcpy(ptr, rcs->buf, 4 * rcs->cdw);
>> +				ptr += rcs->cdw;
>>   
>> -		for (unsigned j = 0; j < cnt; ++j) {
>> -			struct radv_amdgpu_cs *cs = radv_amdgpu_cs(cs_array[i + j]);
>> -			memcpy(ptr, cs->base.buf, 4 * cs->base.cdw);
>> -			ptr += cs->base.cdw;
>> +				for (unsigned k = 0; k < pad_words; ++k)
>> +					*ptr++ = pad_word;
>>   
>> -		}
>> +				ibs[j].size = size;
>> +				ibs[j].ib_mc_address = radv_buffer_get_va(bos[j]);
>> +			}
>>   
>> -		for (unsigned j = 0; j < pad_words; ++j)
>> -			*ptr++ = pad_word;
>> +			number_of_ibs = new_cs_count;
>> +			cnt++;
>> +		} else {
>> +			if (preamble_cs)
>> +				size += preamble_cs->cdw;
>>   
>> -		memset(&request, 0, sizeof(request));
>> +			while (i + cnt < cs_count && 0xffff8 - size >= radv_amdgpu_cs(cs_array[i + cnt])->base.cdw) {
>> +				size += radv_amdgpu_cs(cs_array[i + cnt])->base.cdw;
>> +				++cnt;
>> +			}
>> +
>> +			while (!size || (size & 7)) {
>> +				size++;
>> +				pad_words++;
>> +			}
>> +			assert(cnt);
>>   
>> +			bos[0] = ws->buffer_create(ws, 4 * size, 4096,
>> +						   RADEON_DOMAIN_GTT,
>> +						   RADEON_FLAG_CPU_ACCESS |
>> +						   RADEON_FLAG_NO_INTERPROCESS_SHARING |
>> +						   RADEON_FLAG_READ_ONLY);
>> +			ptr = ws->buffer_map(bos[0]);
>> +
>> +			if (preamble_cs) {
>> +				memcpy(ptr, preamble_cs->buf, preamble_cs->cdw * 4);
>> +				ptr += preamble_cs->cdw;
>> +			}
>> +
>> +			for (unsigned j = 0; j < cnt; ++j) {
>> +				struct radv_amdgpu_cs *cs = radv_amdgpu_cs(cs_array[i + j]);
>> +				memcpy(ptr, cs->base.buf, 4 * cs->base.cdw);
>> +				ptr += cs->base.cdw;
>> +
>> +			}
>> +
>> +			for (unsigned j = 0; j < pad_words; ++j)
>> +				*ptr++ = pad_word;
>> +
>> +			ibs[0].size = size;
>> +			ibs[0].ib_mc_address = radv_buffer_get_va(bos[0]);
>> +		}
>>   
>>   		r = radv_amdgpu_create_bo_list(cs0->ws, &cs_array[i], cnt,
>> -		                               (struct radv_amdgpu_winsys_bo*)bo,
>> -		                               preamble_cs, &bo_list);
>> +			                       (struct radv_amdgpu_winsys_bo **)bos,
>> +					       number_of_ibs, preamble_cs,
>> +					       &bo_list);
>>   		if (r) {
>>   			fprintf(stderr, "amdgpu: buffer list creation failed "
>>   					"for the sysmem submission (%d)\n", r);
>>   			return r;
>>   		}
>>   
>> -		ib.size = size;
>> -		ib.ib_mc_address = radv_buffer_get_va(bo);
>> +		memset(&request, 0, sizeof(request));
>>   
>>   		request.ip_type = cs0->hw_ip;
>>   		request.ring = queue_idx;
>>   		request.resources = bo_list;
>> -		request.number_of_ibs = 1;
>> -		request.ibs = &ib;
>> +		request.number_of_ibs = number_of_ibs;
>> +		request.ibs = ibs;
>>   		request.fence_info = radv_set_cs_fence(ctx, cs0->hw_ip, queue_idx);
>>   
>>   		sem_info->cs_emit_signal = (i == cs_count - cnt) ? emit_signal_sem : false;
>> @@ -934,9 +1051,11 @@ static int radv_amdgpu_winsys_cs_submit_sysmem(struct radeon_winsys_ctx *_ctx,
>>   		if (bo_list)
>>   			amdgpu_bo_list_destroy(bo_list);
>>   
>> -		ws->buffer_destroy(bo);
>> -		if (r)
>> -			return r;
>> +		for (unsigned j = 0; j < number_of_ibs; j++) {
>> +			ws->buffer_destroy(bos[j]);
>> +			if (r)
>> +				return r;
>> +		}
>>   
>>   		i += cnt;
>>   	}


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