On 14/04/2025 18:58, Christian König wrote:
Adding Pierre-eric and Tvrtko as well.

Thanks!

Am 11.04.25 um 15:04 schrieb Sunil Khatri:
Add helper function which get the process information for
the drm_file and updates the user provided character buffer
with the information of process name and pid as a string.

Signed-off-by: Sunil Khatri <sunil.kha...@amd.com>
---
  drivers/gpu/drm/drm_file.c | 30 ++++++++++++++++++++++++++++++
  include/drm/drm_file.h     |  1 +
  2 files changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index cb5f22f5bbb6..4434258d21b5 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -965,6 +965,36 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f)
  }
  EXPORT_SYMBOL(drm_show_fdinfo);
+/**
+ * drm_process_info - Fill info string with process name and pid
+ * @file_priv: context of interest for process name and pid
+ * @proc_info: user char ptr to write the string to
+ * @buff_size: size of the buffer passed for the string
+ *
+ * This update the user provided buffer with process
+ * name and pid information for @file_priv
+ */
+void drm_process_info(struct drm_file *file_priv, char *proc_info, size_t 
buff_size)
+{
+       struct task_struct *task;
+       struct pid *pid;
+       struct drm_device *dev = file_priv->minor->dev;
+
+       if (!proc_info) {
+               drm_err(dev, "Invalid user buffer\n");

I'd replace this with drm_WARN_ON_ONCE.

Another thing I would consider is avoiding the need for stack space by exporting a logging helper instead. Something like (from patch 3/3):

drm_file_err(uq_mgr->file, "Timed out waiting for fence %p\n", f);

Which would output the client name info as a prefix or something.

Especially attractive if you add client name.

Also while here, is %p for the fence is useful? FWIW in the tracing series we are going for %llu:%llu (context:seqno).

Regards,

Tvrtko

+               return;
+       }
+
+       rcu_read_lock();
+       pid = rcu_dereference(file_priv->pid);
+       task = pid_task(pid, PIDTYPE_TGID);
+       if (task)
+               snprintf(proc_info, buff_size, "comm:%s pid:%d", task->comm, 
task->pid);

Looks good in general, but I think people would like to see the optional client 
name here as well.

It's rather useful to have for native context.

Regards,
Christian.

+
+       rcu_read_unlock();
+}
+EXPORT_SYMBOL(drm_process_info);
+
  /**
   * mock_drm_getfile - Create a new struct file for the drm device
   * @minor: drm minor to wrap (e.g. #drm_device.primary)
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index f0ef32e9fa5e..c01b34936968 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -501,6 +501,7 @@ void drm_print_memory_stats(struct drm_printer *p,
void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file);
  void drm_show_fdinfo(struct seq_file *m, struct file *f);
+void drm_process_info(struct drm_file *file_priv, char *proc_info, size_t 
buff_size);
struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);


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