Re: [PATCH] drm/i915: Use hash tables for the command parser

[Damien Lespiau <damien.lespiau@intel.com>]

On Thu, May 08, 2014 at 01:25:33PM +0100, Tvrtko Ursulin wrote:
> 
> On 05/08/2014 12:44 PM, Damien Lespiau wrote:
> >On Thu, May 08, 2014 at 10:56:05AM +0100, Tvrtko Ursulin wrote:
> >>
> >>Hi Brad,
> >>
> >>On 04/28/2014 04:22 PM, bradley.d.volkin@intel.com wrote:
> >>[snip]
> >>>-	BUG_ON(!validate_cmds_sorted(ring));
> >>>+	BUG_ON(!validate_cmds_sorted(ring, cmd_tables, cmd_table_count));
> >>>  	BUG_ON(!validate_regs_sorted(ring));
> >>>+
> >>>+	BUG_ON(init_hash_table(ring, cmd_tables, cmd_table_count));
> >>
> >>Is a BUG_ON a bit harsh since the above fails only on ENOMEM condition?
> >>
> >>If the concern is not allowing any command execution if parser setup
> >>has failed, it would be nicer to the system as whole to just keep
> >>rejecting everything, but let the rest of the kernel live to enable
> >>debug or whatever?
> >
> >Those number_of_cmds allocations are a bit awkward though, couldn't we
> >just embed the hlist_node into the desciptor struct?
> 
> Until Brad comes online, I think that is because command descriptors
> to hash table entries are not 1-to-1.

Ah, I guess the common cmds are part of several hash tables. We could at
least turn the multiple allocations into one big allocation though.

-- 
Damien