Re: [PATCH] drm/i915: Clean-up idr table if context create fails.

Chris Wilson
2015-04-07T08:32:52Z

On Tue, Apr 07, 2015 at 10:20:15AM +0200, Daniel Vetter wrote:
> On Thu, Apr 02, 2015 at 06:49:38PM +0530, Deepak S wrote:
> >
> >
> > On Monday 30 March 2015 09:13 PM, Daniel Vetter wrote:
> > >On Mon, Mar 30, 2015 at 08:03:58PM +0530, deepak.s@linux.intel.com wrote:
> > >>From: Deepak S <deepak.s@linux.intel.com>
> > >>
> > >>Cleanup idr table if any error happens after __create_hw_context() in
> > >>i915_gem_create_context()
> > >>
> > >>Signed-off-by: Deepak S <deepak.s@linux.intel.com>
> > >>---
> > >> drivers/gpu/drm/i915/i915_gem_context.c | 2 ++
> > >> 1 file changed, 2 insertions(+)
> > >>
> > >>diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> > >>index f3e84c4..69bebe5 100644
> > >>--- a/drivers/gpu/drm/i915/i915_gem_context.c
> > >>+++ b/drivers/gpu/drm/i915/i915_gem_context.c
> > >>@@ -287,6 +287,8 @@ err_unpin:
> > >> if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state)
> > >> i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
> > >> err_destroy:
> > >>+ if (ctx->file_priv)
> > >>+ idr_remove(&ctx->file_priv->context_idr, ctx->user_handle);
> > >The common approach is to add a new err_idr: label at the op of the unwind
> > >code and make the call to idr_remove unconditional.
> > >
> > >Thanks, Daniel
> >
> > Thanks Daniel for review.
> > I do not think we can have a unconditional idr remove since for global ctx
> > i915_gem_create_context called with file_priv=NULL?
>
> Hm right, the entire control-flow in there is a bit funny. I think a much
> cleaner solution would be to drop the file_prive from create_context and
> add a new i915_gem_context_create_user which wraps create_context and the
> idr allocation. Doing the cleanup, conditionally, in a different function
> than where we do the allocation is a bit too brittle imo.

I suggested that it look like:
http://cgit.freedesktop.org/~ickle/linux-2.6/tree/drivers/gpu/drm/i915/i915_gem_context.c#n179
-Chris

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Chris Wilson, Intel Open Source Technology Centre