drm/i915: Move debug only per-request pid tracking from request to ctx
authorChris Wilson <chris@chris-wilson.co.uk>
Mon, 15 Aug 2016 09:49:08 +0000 (10:49 +0100)
committerChris Wilson <chris@chris-wilson.co.uk>
Mon, 15 Aug 2016 10:01:15 +0000 (11:01 +0100)
Since contexts are not currently shared between userspace processes, we
have an exact correspondence between context creator and guilty batch
submitter. Therefore we can save some per-batch work by inspecting the
context->pid upon error instead. Note that we take the context's
creator's pid rather than the file's pid in order to better track fd
passed over sockets.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-29-git-send-email-chris@chris-wilson.co.uk
drivers/gpu/drm/i915/i915_debugfs.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_context.c
drivers/gpu/drm/i915/i915_gem_request.c
drivers/gpu/drm/i915/i915_gem_request.h
drivers/gpu/drm/i915/i915_gpu_error.c

index 019df75be5acf6a0da549d0de33dde8c0dd94ed6..1b4de447ae9f06aa39780903b0987f714394f744 100644 (file)
@@ -460,6 +460,8 @@ static int i915_gem_object_info(struct seq_file *m, void* data)
        print_context_stats(m, dev_priv);
        list_for_each_entry_reverse(file, &dev->filelist, lhead) {
                struct file_stats stats;
+               struct drm_i915_file_private *file_priv = file->driver_priv;
+               struct drm_i915_gem_request *request;
                struct task_struct *task;
 
                memset(&stats, 0, sizeof(stats));
@@ -473,10 +475,17 @@ static int i915_gem_object_info(struct seq_file *m, void* data)
                 * still alive (e.g. get_pid(current) => fork() => exit()).
                 * Therefore, we need to protect this ->comm access using RCU.
                 */
+               mutex_lock(&dev->struct_mutex);
+               request = list_first_entry_or_null(&file_priv->mm.request_list,
+                                                  struct drm_i915_gem_request,
+                                                  client_list);
                rcu_read_lock();
-               task = pid_task(file->pid, PIDTYPE_PID);
+               task = pid_task(request && request->ctx->pid ?
+                               request->ctx->pid : file->pid,
+                               PIDTYPE_PID);
                print_file_stats(m, task ? task->comm : "<unknown>", stats);
                rcu_read_unlock();
+               mutex_unlock(&dev->struct_mutex);
        }
        mutex_unlock(&dev->filelist_mutex);
 
@@ -658,12 +667,11 @@ static int i915_gem_request_info(struct seq_file *m, void *data)
 
                seq_printf(m, "%s requests: %d\n", engine->name, count);
                list_for_each_entry(req, &engine->request_list, link) {
+                       struct pid *pid = req->ctx->pid;
                        struct task_struct *task;
 
                        rcu_read_lock();
-                       task = NULL;
-                       if (req->pid)
-                               task = pid_task(req->pid, PIDTYPE_PID);
+                       task = pid ? pid_task(pid, PIDTYPE_PID) : NULL;
                        seq_printf(m, "    %x @ %d: %s [%d]\n",
                                   req->fence.seqno,
                                   (int) (jiffies - req->emitted_jiffies),
@@ -1952,18 +1960,17 @@ static int i915_context_status(struct seq_file *m, void *unused)
 
        list_for_each_entry(ctx, &dev_priv->context_list, link) {
                seq_printf(m, "HW context %u ", ctx->hw_id);
-               if (IS_ERR(ctx->file_priv)) {
-                       seq_puts(m, "(deleted) ");
-               } else if (ctx->file_priv) {
-                       struct pid *pid = ctx->file_priv->file->pid;
+               if (ctx->pid) {
                        struct task_struct *task;
 
-                       task = get_pid_task(pid, PIDTYPE_PID);
+                       task = get_pid_task(ctx->pid, PIDTYPE_PID);
                        if (task) {
                                seq_printf(m, "(%s [%d]) ",
                                           task->comm, task->pid);
                                put_task_struct(task);
                        }
+               } else if (IS_ERR(ctx->file_priv)) {
+                       seq_puts(m, "(deleted) ");
                } else {
                        seq_puts(m, "(kernel) ");
                }
index bd58878de77bc7340ebd630b96aecd324ce45379..d9f29244bafbca2f0d4e2fb28f0b8b8a561ee281 100644 (file)
@@ -782,6 +782,7 @@ struct drm_i915_error_state {
 
                struct drm_i915_error_request {
                        long jiffies;
+                       pid_t pid;
                        u32 seqno;
                        u32 head;
                        u32 tail;
@@ -880,6 +881,7 @@ struct i915_gem_context {
        struct drm_i915_private *i915;
        struct drm_i915_file_private *file_priv;
        struct i915_hw_ppgtt *ppgtt;
+       struct pid *pid;
 
        struct i915_ctx_hang_stats hang_stats;
 
index 98d2956f91f4139a3407003a553fc23ed03b531c..35950ee46a1d35516d349c271fb6a81351af19aa 100644 (file)
@@ -158,6 +158,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
                i915_vma_put(ce->state);
        }
 
+       put_pid(ctx->pid);
        list_del(&ctx->link);
 
        ida_simple_remove(&ctx->i915->context_hw_ida, ctx->hw_id);
@@ -311,6 +312,9 @@ __create_hw_context(struct drm_device *dev,
                ret = DEFAULT_CONTEXT_HANDLE;
 
        ctx->file_priv = file_priv;
+       if (file_priv)
+               ctx->pid = get_task_pid(current, PIDTYPE_PID);
+
        ctx->user_handle = ret;
        /* NB: Mark all slices as needing a remap so that when the context first
         * loads it will restore whatever remap state already exists. If there
index a0756b553a1923ab0c830dae7f1d661a353a8b71..1a215320cefbca539fe136bd6a989d42104fc6fa 100644 (file)
@@ -137,8 +137,6 @@ int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
        list_add_tail(&req->client_list, &file_priv->mm.request_list);
        spin_unlock(&file_priv->mm.lock);
 
-       req->pid = get_pid(task_pid(current));
-
        return 0;
 }
 
@@ -154,9 +152,6 @@ i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
        list_del(&request->client_list);
        request->file_priv = NULL;
        spin_unlock(&file_priv->mm.lock);
-
-       put_pid(request->pid);
-       request->pid = NULL;
 }
 
 void i915_gem_retire_noop(struct i915_gem_active *active,
@@ -407,7 +402,6 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
        req->previous_context = NULL;
        req->file_priv = NULL;
        req->batch = NULL;
-       req->pid = NULL;
        req->elsp_submitted = 0;
 
        /*
index a66243a6f791b25df8b231f2686179515098a0f0..6c72bd8d9423c140cdabbf977eb3f2111bc9dc48 100644 (file)
@@ -134,9 +134,6 @@ struct drm_i915_gem_request {
        /** file_priv list entry for this request */
        struct list_head client_list;
 
-       /** process identifier submitting this request */
-       struct pid *pid;
-
        /**
         * The ELSP only accepts two elements at a time, so we queue
         * context/tail pairs on a given queue (ring->execlist_queue) until the
index 8fc21a9c0abdf561db45ef140e636b9004d6444a..638664f78dd5b2769061318e8b18a8b61653a97e 100644 (file)
@@ -470,7 +470,8 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
                                   dev_priv->engine[i].name,
                                   ee->num_requests);
                        for (j = 0; j < ee->num_requests; j++) {
-                               err_printf(m, "  seqno 0x%08x, emitted %ld, head 0x%08x, tail 0x%08x\n",
+                               err_printf(m, "  pid %d, seqno 0x%08x, emitted %ld, head 0x%08x, tail 0x%08x\n",
+                                          ee->requests[j].pid,
                                           ee->requests[j].seqno,
                                           ee->requests[j].jiffies,
                                           ee->requests[j].head,
@@ -1076,6 +1077,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
                request = i915_gem_find_active_request(engine);
                if (request) {
                        struct intel_ring *ring;
+                       struct pid *pid;
 
                        ee->vm = request->ctx->ppgtt ?
                                &request->ctx->ppgtt->base : &ggtt->base;
@@ -1097,11 +1099,12 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
                                i915_error_object_create(dev_priv,
                                                         request->ctx->engine[i].state);
 
-                       if (request->pid) {
+                       pid = request->ctx->pid;
+                       if (pid) {
                                struct task_struct *task;
 
                                rcu_read_lock();
-                               task = pid_task(request->pid, PIDTYPE_PID);
+                               task = pid_task(pid, PIDTYPE_PID);
                                if (task) {
                                        strcpy(ee->comm, task->comm);
                                        ee->pid = task->pid;
@@ -1166,6 +1169,10 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
                        erq->jiffies = request->emitted_jiffies;
                        erq->head = request->head;
                        erq->tail = request->tail;
+
+                       rcu_read_lock();
+                       erq->pid = request->ctx->pid ? pid_nr(request->ctx->pid) : 0;
+                       rcu_read_unlock();
                }
        }
 }