On Fri, Mar 03, 2017 at 04:52:52PM +0200, Mika Kuoppala wrote: > Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > > > Being inside a spinlock signaling that the hardware just completed a > > request doesn't prevent a second thread already spotting that the > > request is complete, freeing it and reallocating it! The code currently > > tries to prevent this using RCU -- but that only prevents the request > > from being freed, it doesn't prevent us from reallocating it - that > > requires us to take a reference. > > How can it be reallocated if it was never freed in the first place? We use a slab-cache. The pages of the slab themselves are guarded by RCU, but we reallocate from the freelist immediately. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
