| Message ID | 1396676467-21368-1-git-send-email-benjamin.widawsky@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 04, 2014 at 10:41:07PM -0700, Ben Widawsky wrote: > I opted to do this instead of grabbing the context reference after > eb_create since eb_create can potentially call the shrinker, and that > makes things very complicated. This simple patch balances the ref count > without requiring a great deal of review to make sure the shrinker path > is safe. > > Theoretically (by design) the shrinker can end up destroying a context, > which enforces the reasoning for doing the fix this way instead of > moving the reference to later in the function. > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > Signed-off-by: Ben Widawsky <ben@bwidawsk.net> Even the whitespace fix is correct. Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> -Chris
On Sat, Apr 05, 2014 at 07:24:01AM +0100, Chris Wilson wrote: > On Fri, Apr 04, 2014 at 10:41:07PM -0700, Ben Widawsky wrote: > > I opted to do this instead of grabbing the context reference after > > eb_create since eb_create can potentially call the shrinker, and that > > makes things very complicated. This simple patch balances the ref count > > without requiring a great deal of review to make sure the shrinker path > > is safe. > > > > Theoretically (by design) the shrinker can end up destroying a context, > > which enforces the reasoning for doing the fix this way instead of > > moving the reference to later in the function. > > > > Cc: Chris Wilson <chris@chris-wilson.co.uk> > > Signed-off-by: Ben Widawsky <ben@bwidawsk.net> > > Even the whitespace fix is correct. > Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Queued for -next, thanks for the patch. -Daniel
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index e4f0e2c..b785459 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -1133,7 +1133,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, mutex_unlock(&dev->struct_mutex); ret = PTR_ERR(ctx); goto pre_mutex_err; - } + } i915_gem_context_reference(ctx); @@ -1143,6 +1143,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, eb = eb_create(args); if (eb == NULL) { + i915_gem_context_unreference(ctx); mutex_unlock(&dev->struct_mutex); ret = -ENOMEM; goto pre_mutex_err;
I opted to do this instead of grabbing the context reference after eb_create since eb_create can potentially call the shrinker, and that makes things very complicated. This simple patch balances the ref count without requiring a great deal of review to make sure the shrinker path is safe. Theoretically (by design) the shrinker can end up destroying a context, which enforces the reasoning for doing the fix this way instead of moving the reference to later in the function. Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Ben Widawsky <ben@bwidawsk.net> --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)