Quoting Matthew Auld (2019-08-15 20:19:58) > On Wed, 14 Aug 2019 at 10:28, Chris Wilson <ch...@chris-wilson.co.uk> wrote: > > > > In preparation for removing struct_mutex from around context retirement, > > we need to make timeline pinning safe. Since multiple engines/contexts > > can share a single timeline, it needs to be protected by a mutex. > > > > Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> > > With a more accurate commit message, > Reviewed-by: Matthew Auld <matthew.a...@intel.com>
Cruel. In preparation for removing struct_mutex from around context retirement, we need to make timeline pinning and unpinning safe. Since multiple engines/contexts can share a single timeline, we cannot rely on borrowing the context mutex (otherwise we could state that the timeline is only pinned/unpinned inside the context pin/unpin and so guarded by it). However, we only perform a sequence of atomic operations inside the timeline pin/unpin and the sequence of those operations is safe for a concurrent unpin / pin, so we can relax the struct_mutex requirement. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
