[Mesa-dev] [PATCH v2 23/37] panfrost: Make panfrost_batch->bos a hash table

[Alyssa Rosenzweig]

Well, the hash tables strongly assume you're not using NULLs for things.

See _mesa_hash_table_set_deleted_key for how to change that behaviour.

On Mon, Sep 16, 2019 at 04:17:37PM +0200, Boris Brezillon wrote:
> On Mon, 16 Sep 2019 10:00:13 -0400
> Alyssa Rosenzweig <alyssa at rosenzweig.io> wrote:
> 
> > What if flags = 0?
> 
> Not sure what you have in mind. 0 would be a valid value (though not
> really useful since that just means the BO is private and we don't give
> any information on the type of access done on this BO). If you're
> worried about having hentry->data = (uintptr_t)0 (IOW hentry->data =
> NULL), I don't see the problem.
> 
> > 
> > On Mon, Sep 16, 2019 at 11:37:01AM +0200, Boris Brezillon wrote:
> > > So we can store the flags as data and keep the BO as a key. This way
> > > we keep track of the type of access done on BOs.
> > > 
> > > Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> > > ---
> > >  src/gallium/drivers/panfrost/pan_job.c | 33 +++++++++++++++++---------
> > >  src/gallium/drivers/panfrost/pan_job.h |  2 +-
> > >  2 files changed, 23 insertions(+), 12 deletions(-)
> > > 
> > > diff --git a/src/gallium/drivers/panfrost/pan_job.c b/src/gallium/drivers/panfrost/pan_job.c
> > > index 6332529b2f9b..739f36a593f1 100644
> > > --- a/src/gallium/drivers/panfrost/pan_job.c
> > > +++ b/src/gallium/drivers/panfrost/pan_job.c
> > > @@ -44,9 +44,8 @@ panfrost_create_batch(struct panfrost_context *ctx,
> > >  
> > >          batch->ctx = ctx;
> > >  
> > > -        batch->bos = _mesa_set_create(batch,
> > > -                                      _mesa_hash_pointer,
> > > -                                      _mesa_key_pointer_equal);
> > > +        batch->bos = _mesa_hash_table_create(batch, _mesa_hash_pointer,
> > > +                                             _mesa_key_pointer_equal);
> > >  
> > >          batch->minx = batch->miny = ~0;
> > >          batch->maxx = batch->maxy = 0;
> > > @@ -67,10 +66,8 @@ panfrost_free_batch(struct panfrost_batch *batch)
> > >  
> > >          struct panfrost_context *ctx = batch->ctx;
> > >  
> > > -        set_foreach(batch->bos, entry) {
> > > -                struct panfrost_bo *bo = (struct panfrost_bo *)entry->key;
> > > -                panfrost_bo_unreference(bo);
> > > -        }
> > > +        hash_table_foreach(batch->bos, entry)
> > > +                panfrost_bo_unreference((struct panfrost_bo *)entry->key);
> > >  
> > >          _mesa_hash_table_remove_key(ctx->batches, &batch->key);
> > >  
> > > @@ -138,11 +135,25 @@ panfrost_batch_add_bo(struct panfrost_batch *batch, struct panfrost_bo *bo,
> > >          if (!bo)
> > >                  return;
> > >  
> > > -        if (_mesa_set_search(batch->bos, bo))
> > > +        struct hash_entry *entry;
> > > +        uint32_t old_flags = 0;
> > > +
> > > +        entry = _mesa_hash_table_search(batch->bos, bo);
> > > +        if (!entry) {
> > > +                entry = _mesa_hash_table_insert(batch->bos, bo,
> > > +                                                (void *)(uintptr_t)flags);
> > > +                panfrost_bo_reference(bo);
> > > +	} else {
> > > +                old_flags = (uintptr_t)entry->data;
> > > +        }
> > > +
> > > +        assert(entry);
> > > +
> > > +        if (old_flags == flags)
> > >                  return;
> > >  
> > > -        panfrost_bo_reference(bo);
> > > -        _mesa_set_add(batch->bos, bo);
> > > +        flags |= old_flags;
> > > +        entry->data = (void *)(uintptr_t)flags;
> > >  }
> > >  
> > >  void panfrost_batch_add_fbo_bos(struct panfrost_batch *batch)
> > > @@ -376,7 +387,7 @@ panfrost_batch_submit_ioctl(struct panfrost_batch *batch,
> > >          bo_handles = calloc(batch->bos->entries, sizeof(*bo_handles));
> > >          assert(bo_handles);
> > >  
> > > -        set_foreach(batch->bos, entry) {
> > > +        hash_table_foreach(batch->bos, entry) {
> > >                  struct panfrost_bo *bo = (struct panfrost_bo *)entry->key;
> > >                  assert(bo->gem_handle > 0);
> > >                  bo_handles[submit.bo_handle_count++] = bo->gem_handle;
> > > diff --git a/src/gallium/drivers/panfrost/pan_job.h b/src/gallium/drivers/panfrost/pan_job.h
> > > index 0b37a3131e86..3f2cf1a999f3 100644
> > > --- a/src/gallium/drivers/panfrost/pan_job.h
> > > +++ b/src/gallium/drivers/panfrost/pan_job.h
> > > @@ -98,7 +98,7 @@ struct panfrost_batch {
> > >          unsigned job_index;
> > >  
> > >          /* BOs referenced -- will be used for flushing logic */
> > > -        struct set *bos;
> > > +        struct hash_table *bos;
> > >  
> > >          /* Current transient BO */
> > >  	struct panfrost_bo *transient_bo;
> > > -- 
> > > 2.21.0