Module: Mesa Branch: main Commit: 8503cab2e0032dd4d4bd1548919d3c359db82547 URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=8503cab2e0032dd4d4bd1548919d3c359db82547
Author: Alyssa Rosenzweig <[email protected]> Date: Tue Aug 17 17:16:54 2021 +0000 panfrost: Replace writers pointer with hash table This ensures each context can have a separate batch writing a resource and we don't race trying to flush each other's batches. Unfortunately the extra hash table operations regress draw-overhead numbers by about 8% but I'd rather eat the overhead and have an obviously correct implementation than leave known buggy code in tree. Signed-off-by: Alyssa Rosenzweig <[email protected]> Cc: mesa-stable Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12528> --- src/gallium/drivers/panfrost/pan_context.c | 5 +++++ src/gallium/drivers/panfrost/pan_context.h | 3 +++ src/gallium/drivers/panfrost/pan_job.c | 21 ++++++++++++++------- src/gallium/drivers/panfrost/pan_resource.c | 2 +- src/gallium/drivers/panfrost/pan_resource.h | 7 +++++-- 5 files changed, 28 insertions(+), 10 deletions(-) diff --git a/src/gallium/drivers/panfrost/pan_context.c b/src/gallium/drivers/panfrost/pan_context.c index bff821bd9bc..ad94015de6c 100644 --- a/src/gallium/drivers/panfrost/pan_context.c +++ b/src/gallium/drivers/panfrost/pan_context.c @@ -803,6 +803,8 @@ panfrost_destroy(struct pipe_context *pipe) { struct panfrost_context *panfrost = pan_context(pipe); + _mesa_hash_table_destroy(panfrost->writers, NULL); + if (panfrost->blitter) util_blitter_destroy(panfrost->blitter); @@ -1126,6 +1128,9 @@ panfrost_create_context(struct pipe_screen *screen, void *priv, unsigned flags) ctx->blitter = util_blitter_create(gallium); + ctx->writers = _mesa_hash_table_create(gallium, _mesa_hash_pointer, + _mesa_key_pointer_equal); + assert(ctx->blitter); /* Prepare for render! */ diff --git a/src/gallium/drivers/panfrost/pan_context.h b/src/gallium/drivers/panfrost/pan_context.h index 78b39ebaef1..3109bc68858 100644 --- a/src/gallium/drivers/panfrost/pan_context.h +++ b/src/gallium/drivers/panfrost/pan_context.h @@ -146,6 +146,9 @@ struct panfrost_context { BITSET_DECLARE(active, PAN_MAX_BATCHES); } batches; + /* Map from resources to panfrost_batches */ + struct hash_table *writers; + /* Bound job batch */ struct panfrost_batch *batch; diff --git a/src/gallium/drivers/panfrost/pan_job.c b/src/gallium/drivers/panfrost/pan_job.c index 06545dcda0b..049ff9fb98a 100644 --- a/src/gallium/drivers/panfrost/pan_job.c +++ b/src/gallium/drivers/panfrost/pan_job.c @@ -128,8 +128,10 @@ panfrost_batch_cleanup(struct panfrost_batch *batch) set_foreach_remove(batch->resources, entry) { struct panfrost_resource *rsrc = (void *) entry->key; - if (rsrc->track.writer == batch) - rsrc->track.writer = NULL; + if (_mesa_hash_table_search(ctx->writers, rsrc)) { + _mesa_hash_table_remove_key(ctx->writers, rsrc); + rsrc->track.nr_writers--; + } rsrc->track.nr_users--; @@ -238,7 +240,8 @@ panfrost_batch_update_access(struct panfrost_batch *batch, { struct panfrost_context *ctx = batch->ctx; uint32_t batch_idx = panfrost_batch_idx(batch); - struct panfrost_batch *writer = rsrc->track.writer; + struct hash_entry *entry = _mesa_hash_table_search(ctx->writers, rsrc); + struct panfrost_batch *writer = entry ? entry->data : NULL; bool found = false; _mesa_set_search_or_add(batch->resources, rsrc, &found); @@ -267,8 +270,10 @@ panfrost_batch_update_access(struct panfrost_batch *batch, } } - if (writes) - rsrc->track.writer = batch; + if (writes) { + _mesa_hash_table_insert(ctx->writers, rsrc, batch); + rsrc->track.nr_writers++; + } } static void @@ -855,9 +860,11 @@ panfrost_flush_writer(struct panfrost_context *ctx, struct panfrost_resource *rsrc, const char *reason) { - if (rsrc->track.writer) { + struct hash_entry *entry = _mesa_hash_table_search(ctx->writers, rsrc); + + if (entry) { perf_debug_ctx(ctx, "Flushing writer due to: %s", reason); - panfrost_batch_submit(rsrc->track.writer, ctx->syncobj, ctx->syncobj); + panfrost_batch_submit(entry->data, ctx->syncobj, ctx->syncobj); } } diff --git a/src/gallium/drivers/panfrost/pan_resource.c b/src/gallium/drivers/panfrost/pan_resource.c index 6f0c61b86ab..a0539ee340d 100644 --- a/src/gallium/drivers/panfrost/pan_resource.c +++ b/src/gallium/drivers/panfrost/pan_resource.c @@ -874,7 +874,7 @@ panfrost_ptr_map(struct pipe_context *pctx, bool valid = BITSET_TEST(rsrc->valid.data, level); - if ((usage & PIPE_MAP_READ) && (valid || rsrc->track.writer)) { + if ((usage & PIPE_MAP_READ) && (valid || rsrc->track.nr_writers > 0)) { pan_blit_to_staging(pctx, transfer); panfrost_flush_writer(ctx, staging, "AFBC read staging blit"); panfrost_bo_wait(staging->image.data.bo, INT64_MAX, false); diff --git a/src/gallium/drivers/panfrost/pan_resource.h b/src/gallium/drivers/panfrost/pan_resource.h index 6245eb2a424..b0cb3b7485a 100644 --- a/src/gallium/drivers/panfrost/pan_resource.h +++ b/src/gallium/drivers/panfrost/pan_resource.h @@ -48,11 +48,14 @@ struct panfrost_resource { } damage; struct { - struct panfrost_batch *writer; - /** Number of batches accessing this resource. Used to check if * a resource is in use. */ _Atomic unsigned nr_users; + + /** Number of batches writing this resource. Note that only one + * batch per context may write a resource, so this is the + * number of contexts that have an active writer. */ + _Atomic unsigned nr_writers; } track; struct renderonly_scanout *scanout;
