[Mesa-dev] [PATCH] r600g: avoid shader needing too many gpr to lockup the gpu
Marek Olšák
maraeo at gmail.com
Sat Oct 27 07:12:43 PDT 2012
FWIW, instead of putting the discard_draw flag in r600_context, it
would be cleaner to have r600_adjust_gprs return false if drawing
should be skipped, then r600_update_derived_state would return false
and draw_vbo would skip rendering. That way you wouldn't have to add
any comments in draw_vbo, because it would be clear where the error is
coming from.
Using R600_ERR to report the error should be sufficient.
r600_adjust_gprs seems to be the best place for that.
Marek
On Sat, Oct 27, 2012 at 3:47 AM, Jerome Glisse <j.glisse at gmail.com> wrote:
> On Fri, Oct 26, 2012 at 10:01 PM, <j.glisse at gmail.com> wrote:
>> From: Jerome Glisse <jglisse at redhat.com>
>>
>> On r6xx/r7xx shader resource management need to make sure that the
>> shader does not goes over the gpr register limit. Each specific
>> asic has a maxmimum register that can be split btw shader stage.
>> For each stage the shader must not use more register than the
>> limit programmed.
>>
>> Signed-off-by: Jerome Glisse <jglisse at redhat.com>
>
> I haven't yet fully tested it on wide range of GPU but it fixes piglit
> case that were locking up o one can directly use quick-drivers. I
> mostly would like feedback on if we should print a warning when we
> discard a draw command because shader exceed limit.
>
> Note that with this patch the test that were locking up fails but with
> a simple patch on top of that (decreasing clause temp gpr to 2) they
> pass.
>
> Regards,
> Jerome
>
>> ---
>> src/gallium/drivers/r600/r600_pipe.h | 1 +
>> src/gallium/drivers/r600/r600_state.c | 60 +++++++++++++++++++---------
>> src/gallium/drivers/r600/r600_state_common.c | 22 +++++-----
>> 3 files changed, 55 insertions(+), 28 deletions(-)
>>
>> diff --git a/src/gallium/drivers/r600/r600_pipe.h b/src/gallium/drivers/r600/r600_pipe.h
>> index ff2a5fd..2045af3 100644
>> --- a/src/gallium/drivers/r600/r600_pipe.h
>> +++ b/src/gallium/drivers/r600/r600_pipe.h
>> @@ -363,6 +363,7 @@ struct r600_context {
>> enum chip_class chip_class;
>> boolean has_vertex_cache;
>> boolean keep_tiling_flags;
>> + bool discard_draw;
>> unsigned default_ps_gprs, default_vs_gprs;
>> unsigned r6xx_num_clause_temp_gprs;
>> unsigned backend_mask;
>> diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
>> index 7d07008..43af934 100644
>> --- a/src/gallium/drivers/r600/r600_state.c
>> +++ b/src/gallium/drivers/r600/r600_state.c
>> @@ -2189,30 +2189,54 @@ void r600_init_state_functions(struct r600_context *rctx)
>> /* Adjust GPR allocation on R6xx/R7xx */
>> void r600_adjust_gprs(struct r600_context *rctx)
>> {
>> - unsigned num_ps_gprs = rctx->default_ps_gprs;
>> - unsigned num_vs_gprs = rctx->default_vs_gprs;
>> + unsigned num_ps_gprs = rctx->ps_shader->current->shader.bc.ngpr;
>> + unsigned num_vs_gprs = rctx->vs_shader->current->shader.bc.ngpr;
>> + unsigned new_num_ps_gprs = num_ps_gprs;
>> + unsigned new_num_vs_gprs = num_vs_gprs;
>> + unsigned cur_num_ps_gprs = G_008C04_NUM_PS_GPRS(rctx->config_state.sq_gpr_resource_mgmt_1);
>> + unsigned cur_num_vs_gprs = G_008C04_NUM_VS_GPRS(rctx->config_state.sq_gpr_resource_mgmt_1);
>> + unsigned def_num_ps_gprs = rctx->default_ps_gprs;
>> + unsigned def_num_vs_gprs = rctx->default_vs_gprs;
>> + unsigned def_num_clause_temp_gprs = rctx->r6xx_num_clause_temp_gprs;
>> + /* hardware will reserve twice num_clause_temp_gprs */
>> + unsigned max_gprs = def_num_ps_gprs + def_num_vs_gprs + def_num_clause_temp_gprs * 2;
>> unsigned tmp;
>> - int diff;
>>
>> - if (rctx->ps_shader->current->shader.bc.ngpr > rctx->default_ps_gprs) {
>> - diff = rctx->ps_shader->current->shader.bc.ngpr - rctx->default_ps_gprs;
>> - num_vs_gprs -= diff;
>> - num_ps_gprs += diff;
>> + /* the sum of all SQ_GPR_RESOURCE_MGMT*.NUM_*_GPRS must <= to max_gprs */
>> + if (new_num_ps_gprs > cur_num_ps_gprs || new_num_vs_gprs > cur_num_vs_gprs) {
>> + /* try to use switch back to default */
>> + if (new_num_ps_gprs > def_num_ps_gprs || new_num_vs_gprs > def_num_vs_gprs) {
>> + /* always privilege vs stage so that at worst we have the
>> + * pixel stage producing wrong output (not the vertex
>> + * stage) */
>> + new_num_ps_gprs = max_gprs - (new_num_vs_gprs + def_num_clause_temp_gprs * 2);
>> + new_num_vs_gprs = num_vs_gprs;
>> + } else {
>> + new_num_ps_gprs = def_num_ps_gprs;
>> + new_num_vs_gprs = def_num_vs_gprs;
>> + }
>> + } else {
>> + rctx->discard_draw = false;
>> + return;
>> }
>>
>> - if (rctx->vs_shader->current->shader.bc.ngpr > rctx->default_vs_gprs)
>> - {
>> - diff = rctx->vs_shader->current->shader.bc.ngpr - rctx->default_vs_gprs;
>> - num_ps_gprs -= diff;
>> - num_vs_gprs += diff;
>> + /* SQ_PGM_RESOURCES_*.NUM_GPRS must always be program to a value <=
>> + * SQ_GPR_RESOURCE_MGMT*.NUM_*_GPRS otherwise the GPU will lockup
>> + * Also if a shader use more gpr than SQ_GPR_RESOURCE_MGMT*.NUM_*_GPRS
>> + * it will lockup. So in this case just discard the draw command
>> + * and don't change the current gprs repartitions.
>> + */
>> + rctx->discard_draw = false;
>> + if (num_ps_gprs > new_num_ps_gprs || num_vs_gprs > new_num_vs_gprs) {
>> + rctx->discard_draw = true;
>> + return;
>> }
>>
>> - tmp = 0;
>> - tmp |= S_008C04_NUM_PS_GPRS(num_ps_gprs);
>> - tmp |= S_008C04_NUM_VS_GPRS(num_vs_gprs);
>> - tmp |= S_008C04_NUM_CLAUSE_TEMP_GPRS(rctx->r6xx_num_clause_temp_gprs);
>> -
>> - if (tmp != rctx->config_state.sq_gpr_resource_mgmt_1) {
>> + /* in some case we endup recomputing the current value */
>> + tmp = S_008C04_NUM_PS_GPRS(new_num_ps_gprs) |
>> + S_008C04_NUM_VS_GPRS(new_num_vs_gprs) |
>> + S_008C04_NUM_CLAUSE_TEMP_GPRS(def_num_clause_temp_gprs);
>> + if (rctx->config_state.sq_gpr_resource_mgmt_1 != tmp) {
>> rctx->config_state.sq_gpr_resource_mgmt_1 = tmp;
>> rctx->config_state.atom.dirty = true;
>> rctx->flags |= R600_CONTEXT_PS_PARTIAL_FLUSH;
>> diff --git a/src/gallium/drivers/r600/r600_state_common.c b/src/gallium/drivers/r600/r600_state_common.c
>> index 65985c7..5827efb 100644
>> --- a/src/gallium/drivers/r600/r600_state_common.c
>> +++ b/src/gallium/drivers/r600/r600_state_common.c
>> @@ -755,10 +755,6 @@ static int r600_shader_select(struct pipe_context *ctx,
>> shader->next_variant = sel->current;
>> sel->current = shader;
>>
>> - if (rctx->chip_class < EVERGREEN && rctx->ps_shader && rctx->vs_shader) {
>> - r600_adjust_gprs(rctx);
>> - }
>> -
>> if (rctx->ps_shader &&
>> rctx->cb_misc_state.nr_ps_color_outputs != rctx->ps_shader->current->nr_ps_color_outputs) {
>> rctx->cb_misc_state.nr_ps_color_outputs = rctx->ps_shader->current->nr_ps_color_outputs;
>> @@ -814,9 +810,6 @@ static void r600_bind_ps_state(struct pipe_context *ctx, void *state)
>> rctx->cb_misc_state.multiwrite = multiwrite;
>> rctx->cb_misc_state.atom.dirty = true;
>> }
>> -
>> - if (rctx->vs_shader)
>> - r600_adjust_gprs(rctx);
>> }
>>
>> if (rctx->cb_misc_state.nr_ps_color_outputs != rctx->ps_shader->current->nr_ps_color_outputs) {
>> @@ -839,9 +832,6 @@ static void r600_bind_vs_state(struct pipe_context *ctx, void *state)
>> if (state) {
>> r600_context_pipe_state_set(rctx, &rctx->vs_shader->current->rstate);
>>
>> - if (rctx->chip_class < EVERGREEN && rctx->ps_shader)
>> - r600_adjust_gprs(rctx);
>> -
>> /* Update clip misc state. */
>> if (rctx->vs_shader->current->pa_cl_vs_out_cntl != rctx->clip_misc_state.pa_cl_vs_out_cntl ||
>> rctx->vs_shader->current->shader.clip_dist_write != rctx->clip_misc_state.clip_dist_write) {
>> @@ -1055,6 +1045,10 @@ static void r600_update_derived_state(struct r600_context *rctx)
>>
>> r600_shader_select(ctx, rctx->ps_shader, &ps_dirty);
>>
>> + if (rctx->chip_class < EVERGREEN && rctx->ps_shader && rctx->vs_shader) {
>> + r600_adjust_gprs(rctx);
>> + }
>> +
>> if (rctx->ps_shader && rctx->rasterizer &&
>> ((rctx->rasterizer->sprite_coord_enable != rctx->ps_shader->current->sprite_coord_enable) ||
>> (rctx->rasterizer->flatshade != rctx->ps_shader->current->flatshade))) {
>> @@ -1139,6 +1133,14 @@ static void r600_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info
>>
>> r600_update_derived_state(rctx);
>>
>> + if (rctx->discard_draw) {
>> + /* no need to clutter command stream with useless state
>> + * state change. Draw call are discarded if shader is
>> + * over the limit. See r600_adjust_gprs
>> + */
>> + return;
>> + }
>> +
>> if (info.indexed) {
>> /* Initialize the index buffer struct. */
>> pipe_resource_reference(&ib.buffer, rctx->index_buffer.buffer);
>> --
>> 1.7.11.7
>>
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