drm/i915: Drop spinlocks around adding to the client request list
Adding to the tail of the client request list as the only other user is
in the throttle ioctl that iterates forwards over the list. It only
needs protection against deletion of a request as it reads it, it simply
won't see a new request added to the end of the list, or it would be too
early and rejected. We can further reduce the number of spinlocks
required when throttling by removing stale requests from the client_list
as we throttle.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170302122525.19675-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index aa75ea2..dd7181e 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1407,6 +1407,14 @@ i915_gem_execbuffer_parse(struct intel_engine_cs *engine,
return vma;
}
+static void
+add_to_client(struct drm_i915_gem_request *req,
+ struct drm_file *file)
+{
+ req->file_priv = file->driver_priv;
+ list_add_tail(&req->client_link, &req->file_priv->mm.request_list);
+}
+
static int
execbuf_submit(struct i915_execbuffer_params *params,
struct drm_i915_gem_execbuffer2 *args,
@@ -1772,10 +1780,6 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
*/
params->request->batch = params->batch;
- ret = i915_gem_request_add_to_client(params->request, file);
- if (ret)
- goto err_request;
-
/*
* Save assorted stuff away to pass through to *_submission().
* NB: This data should be 'persistent' and not local as it will
@@ -1793,6 +1797,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
ret = execbuf_submit(params, args, &eb->vmas);
err_request:
__i915_add_request(params->request, ret == 0);
+ add_to_client(params->request, file);
+
if (out_fence) {
if (ret == 0) {
fd_install(out_fence_fd, out_fence->file);