[Mesa-dev] [PATCH 15/17] radeonsi: always prefetch later shaders after the draw packet
Marek Olšák
maraeo at gmail.com
Wed Apr 4 12:59:47 UTC 2018
On Wed, Apr 4, 2018, 6:07 AM Samuel Pitoiset <samuel.pitoiset at gmail.com>
wrote:
>
>
> On 04/04/2018 03:59 AM, Marek Olšák wrote:
> > From: Marek Olšák <marek.olsak at amd.com>
> >
> > so that the draw is started as soon as possible.
> > ---
> > src/gallium/drivers/radeonsi/si_cp_dma.c | 68
> ++++++++++++++++++----------
> > src/gallium/drivers/radeonsi/si_pipe.h | 2 +-
> > src/gallium/drivers/radeonsi/si_state_draw.c | 11 ++++-
> > src/util/bitscan.h | 8 ++++
> > 4 files changed, 61 insertions(+), 28 deletions(-)
> >
> > diff --git a/src/gallium/drivers/radeonsi/si_cp_dma.c
> b/src/gallium/drivers/radeonsi/si_cp_dma.c
> > index 15bd305a350..ea2c7cf7198 100644
> > --- a/src/gallium/drivers/radeonsi/si_cp_dma.c
> > +++ b/src/gallium/drivers/radeonsi/si_cp_dma.c
> > @@ -514,80 +514,98 @@ static void cik_prefetch_shader_async(struct
> si_context *sctx,
> > static void cik_prefetch_VBO_descriptors(struct si_context *sctx)
> > {
> > if (!sctx->vertex_elements)
> > return;
> >
> > cik_prefetch_TC_L2_async(sctx, &sctx->vb_descriptors_buffer->b.b,
> > sctx->vb_descriptors_offset,
> >
> sctx->vertex_elements->desc_list_byte_size);
> > }
> >
> > -void cik_emit_prefetch_L2(struct si_context *sctx)
> > +/**
> > + * Prefetch shaders and VBO descriptors.
> > + *
> > + * \param first_two Whether only the first 2 items should be
> prefetched,
> > + * which are usually the API VS and VBO descriptors.
> > + */
> > +void cik_emit_prefetch_L2(struct si_context *sctx, bool first_two)
> > {
> > + unsigned mask;
> > +
> > + assert(sctx->prefetch_L2_mask);
> > +
> > + if (first_two) {
> > + mask = 1 << u_bit_scan16(&sctx->prefetch_L2_mask);
> > +
> > + if (sctx->prefetch_L2_mask)
> > + mask |= 1 << u_bit_scan16(&sctx->prefetch_L2_mask);
>
> Where do you reset the prefetch L2 mask ? It looks like to me that you
> are going to prefetch VS/VBOs twice in the fast draw path.
>
u_bit_scan16 clears the returned bit.
Marek
> + } else {
> > + mask = sctx->prefetch_L2_mask;
> > + sctx->prefetch_L2_mask = 0;
> > + }
> > +
> > /* Prefetch shaders and VBO descriptors to TC L2. */
> > if (sctx->b.chip_class >= GFX9) {
> > /* Choose the right spot for the VBO prefetch. */
> > if (sctx->tes_shader.cso) {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_HS)
> > + if (mask & SI_PREFETCH_HS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.hs);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
> > + if (mask & SI_PREFETCH_GS)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.gs);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > } else if (sctx->gs_shader.cso) {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
> > + if (mask & SI_PREFETCH_GS)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.gs);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > } else {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > }
> > } else {
> > /* SI-CI-VI */
> > /* Choose the right spot for the VBO prefetch. */
> > if (sctx->tes_shader.cso) {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_LS)
> > + if (mask & SI_PREFETCH_LS)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.ls);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_HS)
> > + if (mask & SI_PREFETCH_HS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.hs);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_ES)
> > + if (mask & SI_PREFETCH_ES)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.es);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
> > + if (mask & SI_PREFETCH_GS)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.gs);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > } else if (sctx->gs_shader.cso) {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_ES)
> > + if (mask & SI_PREFETCH_ES)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.es);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_GS)
> > + if (mask & SI_PREFETCH_GS)
> > cik_prefetch_shader_async(sctx, sctx->
> queued.named.gs);
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > } else {
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_VS)
> > + if (mask & SI_PREFETCH_VS)
> > cik_prefetch_shader_async(sctx,
> sctx->queued.named.vs);
> > - if (sctx->prefetch_L2_mask &
> SI_PREFETCH_VBO_DESCRIPTORS)
> > + if (mask & SI_PREFETCH_VBO_DESCRIPTORS)
> > cik_prefetch_VBO_descriptors(sctx);
> > }
> > }
> >
> > - if (sctx->prefetch_L2_mask & SI_PREFETCH_PS)
> > + if (mask & SI_PREFETCH_PS)
> > cik_prefetch_shader_async(sctx, sctx->queued.named.ps);
> > -
> > - sctx->prefetch_L2_mask = 0;
> > }
> >
> > void si_init_cp_dma_functions(struct si_context *sctx)
> > {
> > sctx->b.b.clear_buffer = si_pipe_clear_buffer;
> > }
> > diff --git a/src/gallium/drivers/radeonsi/si_pipe.h
> b/src/gallium/drivers/radeonsi/si_pipe.h
> > index bb1aebdda42..62641fde5e3 100644
> > --- a/src/gallium/drivers/radeonsi/si_pipe.h
> > +++ b/src/gallium/drivers/radeonsi/si_pipe.h
> > @@ -688,21 +688,21 @@ enum r600_coherency {
> >
> > void si_clear_buffer(struct pipe_context *ctx, struct pipe_resource
> *dst,
> > uint64_t offset, uint64_t size, unsigned value,
> > enum r600_coherency coher);
> > void si_copy_buffer(struct si_context *sctx,
> > struct pipe_resource *dst, struct pipe_resource *src,
> > uint64_t dst_offset, uint64_t src_offset, unsigned
> size,
> > unsigned user_flags);
> > void cik_prefetch_TC_L2_async(struct si_context *sctx, struct
> pipe_resource *buf,
> > uint64_t offset, unsigned size);
> > -void cik_emit_prefetch_L2(struct si_context *sctx);
> > +void cik_emit_prefetch_L2(struct si_context *sctx, bool first_two);
> > void si_init_cp_dma_functions(struct si_context *sctx);
> >
> > /* si_debug.c */
> > void si_auto_log_cs(void *data, struct u_log_context *log);
> > void si_log_hw_flush(struct si_context *sctx);
> > void si_log_draw_state(struct si_context *sctx, struct u_log_context
> *log);
> > void si_log_compute_state(struct si_context *sctx, struct
> u_log_context *log);
> > void si_init_debug_functions(struct si_context *sctx);
> > void si_check_vm_faults(struct r600_common_context *ctx,
> > struct radeon_saved_cs *saved, enum ring_type
> ring);
> > diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c
> b/src/gallium/drivers/radeonsi/si_state_draw.c
> > index 1e79ccca054..8446b1b50bc 100644
> > --- a/src/gallium/drivers/radeonsi/si_state_draw.c
> > +++ b/src/gallium/drivers/radeonsi/si_state_draw.c
> > @@ -1450,36 +1450,43 @@ void si_draw_vbo(struct pipe_context *ctx, const
> struct pipe_draw_info *info)
> > sctx->b.render_cond_atom.emit(&sctx->b, NULL);
> > sctx->dirty_atoms = 0;
> >
> > si_emit_draw_packets(sctx, info, indexbuf, index_size,
> index_offset);
> > /* <-- CUs are busy here. */
> >
> > /* Start prefetches after the draw has been started. Both
> will run
> > * in parallel, but starting the draw first is more
> important.
> > */
> > if (sctx->b.chip_class >= CIK && sctx->prefetch_L2_mask)
> > - cik_emit_prefetch_L2(sctx);
> > + cik_emit_prefetch_L2(sctx, false);
> > } else {
> > /* If we don't wait for idle, start prefetches first, then
> set
> > * states, and draw at the end.
> > */
> > if (sctx->b.flags)
> > si_emit_cache_flush(sctx);
> >
> > + /* Only prefetch the first 2 items, e.g. the API VS and VBO
> > + * descriptors. */
> > if (sctx->b.chip_class >= CIK && sctx->prefetch_L2_mask)
> > - cik_emit_prefetch_L2(sctx);
> > + cik_emit_prefetch_L2(sctx, true);
> >
> > if (!si_upload_graphics_shader_descriptors(sctx))
> > return;
> >
> > si_emit_all_states(sctx, info, 0);
> > si_emit_draw_packets(sctx, info, indexbuf, index_size,
> index_offset);
> > +
> > + /* Prefetch the remaining shaders after the draw has been
> > + * started. */
> > + if (sctx->b.chip_class >= CIK && sctx->prefetch_L2_mask)
> > + cik_emit_prefetch_L2(sctx, false);
> > }
> >
> > if (unlikely(sctx->current_saved_cs)) {
> > si_trace_emit(sctx);
> > si_log_draw_state(sctx, sctx->b.log);
> > }
> >
> > /* Workaround for a VGT hang when streamout is enabled.
> > * It must be done after drawing. */
> > if ((sctx->b.family == CHIP_HAWAII ||
> > diff --git a/src/util/bitscan.h b/src/util/bitscan.h
> > index 5cc75f0beba..78ff8e0cea1 100644
> > --- a/src/util/bitscan.h
> > +++ b/src/util/bitscan.h
> > @@ -89,20 +89,28 @@ ffsll(long long int val);
> >
> >
> > /* Destructively loop over all of the bits in a mask as in:
> > *
> > * while (mymask) {
> > * int i = u_bit_scan(&mymask);
> > * ... process element i
> > * }
> > *
> > */
> > +static inline int
> > +u_bit_scan16(uint16_t *mask)
> > +{
> > + const int i = ffs(*mask) - 1;
> > + *mask ^= (1u << i);
> > + return i;
> > +}
> > +
> > static inline int
> > u_bit_scan(unsigned *mask)
> > {
> > const int i = ffs(*mask) - 1;
> > *mask ^= (1u << i);
> > return i;
> > }
> >
> > static inline int
> > u_bit_scan64(uint64_t *mask)
> >
>
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