drm/i915/selftests: Exercise independence of per-engine resets

If all goes well, resetting one engine should not affect the operation of
any others. So to test this, we setup a continuous stream of requests
onto to each of the "innocent" engines whilst constantly resetting our
target engine.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Michel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170721123238.16428-16-chris@chris-wilson.co.uk
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index 7096c39..cf589e3 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -22,8 +22,13 @@
  *
  */
 
+#include <linux/kthread.h>
+
 #include "../i915_selftest.h"
 
+#include "mock_context.h"
+#include "mock_drm.h"
+
 struct hang {
        struct drm_i915_private *i915;
        struct drm_i915_gem_object *hws;
@@ -372,6 +377,164 @@ static int igt_reset_engine(void *arg)
        return err;
 }
 
+static int active_engine(void *data)
+{
+       struct intel_engine_cs *engine = data;
+       struct drm_i915_gem_request *rq[2] = {};
+       struct i915_gem_context *ctx[2];
+       struct drm_file *file;
+       unsigned long count = 0;
+       int err = 0;
+
+       file = mock_file(engine->i915);
+       if (IS_ERR(file))
+               return PTR_ERR(file);
+
+       mutex_lock(&engine->i915->drm.struct_mutex);
+       ctx[0] = live_context(engine->i915, file);
+       mutex_unlock(&engine->i915->drm.struct_mutex);
+       if (IS_ERR(ctx[0])) {
+               err = PTR_ERR(ctx[0]);
+               goto err_file;
+       }
+
+       mutex_lock(&engine->i915->drm.struct_mutex);
+       ctx[1] = live_context(engine->i915, file);
+       mutex_unlock(&engine->i915->drm.struct_mutex);
+       if (IS_ERR(ctx[1])) {
+               err = PTR_ERR(ctx[1]);
+               i915_gem_context_put(ctx[0]);
+               goto err_file;
+       }
+
+       while (!kthread_should_stop()) {
+               unsigned int idx = count++ & 1;
+               struct drm_i915_gem_request *old = rq[idx];
+               struct drm_i915_gem_request *new;
+
+               mutex_lock(&engine->i915->drm.struct_mutex);
+               new = i915_gem_request_alloc(engine, ctx[idx]);
+               if (IS_ERR(new)) {
+                       mutex_unlock(&engine->i915->drm.struct_mutex);
+                       err = PTR_ERR(new);
+                       break;
+               }
+
+               rq[idx] = i915_gem_request_get(new);
+               i915_add_request(new);
+               mutex_unlock(&engine->i915->drm.struct_mutex);
+
+               if (old) {
+                       i915_wait_request(old, 0, MAX_SCHEDULE_TIMEOUT);
+                       i915_gem_request_put(old);
+               }
+       }
+
+       for (count = 0; count < ARRAY_SIZE(rq); count++)
+               i915_gem_request_put(rq[count]);
+
+err_file:
+       mock_file_free(engine->i915, file);
+       return err;
+}
+
+static int igt_reset_active_engines(void *arg)
+{
+       struct drm_i915_private *i915 = arg;
+       struct intel_engine_cs *engine, *active;
+       enum intel_engine_id id, tmp;
+       int err = 0;
+
+       /* Check that issuing a reset on one engine does not interfere
+        * with any other engine.
+        */
+
+       if (!intel_has_reset_engine(i915))
+               return 0;
+
+       for_each_engine(engine, i915, id) {
+               struct task_struct *threads[I915_NUM_ENGINES];
+               unsigned long resets[I915_NUM_ENGINES];
+               unsigned long global = i915_reset_count(&i915->gpu_error);
+               IGT_TIMEOUT(end_time);
+
+               memset(threads, 0, sizeof(threads));
+               for_each_engine(active, i915, tmp) {
+                       struct task_struct *tsk;
+
+                       if (active == engine)
+                               continue;
+
+                       resets[tmp] = i915_reset_engine_count(&i915->gpu_error,
+                                                             active);
+
+                       tsk = kthread_run(active_engine, active,
+                                         "igt/%s", active->name);
+                       if (IS_ERR(tsk)) {
+                               err = PTR_ERR(tsk);
+                               goto unwind;
+                       }
+
+                       threads[tmp] = tsk;
+                       get_task_struct(tsk);
+               }
+
+               set_bit(I915_RESET_ENGINE + engine->id, &i915->gpu_error.flags);
+               do {
+                       err = i915_reset_engine(engine);
+                       if (err) {
+                               pr_err("i915_reset_engine(%s) failed, err=%d\n",
+                                      engine->name, err);
+                               break;
+                       }
+               } while (time_before(jiffies, end_time));
+               clear_bit(I915_RESET_ENGINE + engine->id,
+                         &i915->gpu_error.flags);
+
+unwind:
+               for_each_engine(active, i915, tmp) {
+                       int ret;
+
+                       if (!threads[tmp])
+                               continue;
+
+                       ret = kthread_stop(threads[tmp]);
+                       if (ret) {
+                               pr_err("kthread for active engine %s failed, err=%d\n",
+                                      active->name, ret);
+                               if (!err)
+                                       err = ret;
+                       }
+                       put_task_struct(threads[tmp]);
+
+                       if (resets[tmp] != i915_reset_engine_count(&i915->gpu_error,
+                                                                  active)) {
+                               pr_err("Innocent engine %s was reset (count=%ld)\n",
+                                      active->name,
+                                      i915_reset_engine_count(&i915->gpu_error,
+                                                              active) - resets[tmp]);
+                               err = -EIO;
+                       }
+               }
+
+               if (global != i915_reset_count(&i915->gpu_error)) {
+                       pr_err("Global reset (count=%ld)!\n",
+                              i915_reset_count(&i915->gpu_error) - global);
+                       err = -EIO;
+               }
+
+               if (err)
+                       break;
+
+               cond_resched();
+       }
+
+       if (i915_terminally_wedged(&i915->gpu_error))
+               err = -EIO;
+
+       return err;
+}
+
 static u32 fake_hangcheck(struct drm_i915_gem_request *rq)
 {
        u32 reset_count;
@@ -689,6 +852,7 @@ int intel_hangcheck_live_selftests(struct drm_i915_private *i915)
                SUBTEST(igt_hang_sanitycheck),
                SUBTEST(igt_global_reset),
                SUBTEST(igt_reset_engine),
+               SUBTEST(igt_reset_active_engines),
                SUBTEST(igt_wait_reset),
                SUBTEST(igt_reset_queue),
                SUBTEST(igt_render_engine_reset_fallback),

diff --git a/drivers/gpu/drm/i915/selftests/mock_context.c b/drivers/gpu/drm/i915/selftests/mock_context.c
index 9c7c681..d436f2d 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_context.c
+++ b/drivers/gpu/drm/i915/selftests/mock_context.c
@@ -95,3 +95,11 @@ void mock_init_contexts(struct drm_i915_private *i915)
        INIT_WORK(&i915->contexts.free_work, contexts_free_worker);
        init_llist_head(&i915->contexts.free_list);
 }
+
+struct i915_gem_context *
+live_context(struct drm_i915_private *i915, struct drm_file *file)
+{
+       lockdep_assert_held(&i915->drm.struct_mutex);
+
+       return i915_gem_create_context(i915, file->driver_priv);
+}

diff --git a/drivers/gpu/drm/i915/selftests/mock_context.h b/drivers/gpu/drm/i915/selftests/mock_context.h
index 383941a..2f432c0 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/mock_context.h
+++ b/drivers/gpu/drm/i915/selftests/mock_context.h
@@ -33,4 +33,7 @@ mock_context(struct drm_i915_private *i915,
 
 void mock_context_close(struct i915_gem_context *ctx);
 
+struct i915_gem_context *
+live_context(struct drm_i915_private *i915, struct drm_file *file);
+
 #endif /* !__MOCK_CONTEXT_H */