drm/i915: Move debug only per-request pid tracking from request to ctx
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
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 019df75..1b4de44 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -460,6 +460,8 @@
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 @@
* 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 @@
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 @@
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) ");
}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index bd58878..d9f2924 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -782,6 +782,7 @@
struct drm_i915_error_request {
long jiffies;
+ pid_t pid;
u32 seqno;
u32 head;
u32 tail;
@@ -880,6 +881,7 @@
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;
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 98d2956..35950ee 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -158,6 +158,7 @@
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 @@
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
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index a0756b5..1a21532 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -137,8 +137,6 @@
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 @@
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 @@
req->previous_context = NULL;
req->file_priv = NULL;
req->batch = NULL;
- req->pid = NULL;
req->elsp_submitted = 0;
/*
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index a66243a..6c72bd8 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -134,9 +134,6 @@
/** 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
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 8fc21a9..638664f 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -470,7 +470,8 @@
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 @@
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 @@
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 @@
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();
}
}
}