Quoting Chris Wilson (2017-11-14 16:27:19) > Ages ago Rob Clark noted, > > "Currently with fence-array, we have a potential deadlock situation. If > we fence_add_callback() on an array-fence, the array-fence's lock is > acquired first, and in it's ->enable_signaling() callback, it will install > cbs on it's array-member fences, so the array-member's lock is acquired > second. > > But in the signal path, the array-member's lock is acquired first, and > the array-fence's lock acquired second." > > Rob proposed either extensive changes to dma-fence to unnest the > fence-array signaling, or to defer the signaling onto a workqueue. This > is a more refined version of the later, that should keep the latency > of the fence signaling to a minimum by using an irq-work, which is > executed asap. > > Reported-by: Rob Clark <[email protected]> > Suggested-by: Rob Clark <[email protected]>
Testcase: igt/sw_sync/sync_multi_timeline_wait > References: [email protected] > Signed-off-by: Chris Wilson <[email protected]> > Cc: Rob Clark <[email protected]> > Cc: Gustavo Padovan <[email protected]> > Cc: Sumit Semwal <[email protected]> > Cc: Christian König <[email protected]> _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
