[Intel-gfx] [PATCH igt 1/2] lib/dummyload: Wrap global list inside its own mutex

[Tvrtko Ursulin]

On 12/12/2017 12:21, Chris Wilson wrote:
> Give the list a mutex, for we try to iterate over it from many a random
> context.

Isn't it only tests and their exit handlers, so already serialized?

Should spin batches instead install an exit handler?

Regards,

Tvrtko

> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   lib/igt_dummyload.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/lib/igt_dummyload.c b/lib/igt_dummyload.c
> index bb2be557a..d19b4e5ea 100644
> --- a/lib/igt_dummyload.c
> +++ b/lib/igt_dummyload.c
> @@ -57,6 +57,7 @@
>   
>   static const int BATCH_SIZE = 4096;
>   static IGT_LIST(spin_list);
> +static pthread_mutex_t list_lock = PTHREAD_MUTEX_INITIALIZER;
>   
>   static void
>   fill_reloc(struct drm_i915_gem_relocation_entry *reloc,
> @@ -182,7 +183,9 @@ __igt_spin_batch_new(int fd, uint32_t ctx, unsigned engine, uint32_t dep)
>   	emit_recursive_batch(spin, fd, ctx, engine, dep);
>   	igt_assert(gem_bo_busy(fd, spin->handle));
>   
> +	pthread_mutex_lock(&list_lock);
>   	igt_list_add(&spin->link, &spin_list);
> +	pthread_mutex_unlock(&list_lock);
>   
>   	return spin;
>   }
> @@ -281,7 +284,9 @@ void igt_spin_batch_free(int fd, igt_spin_t *spin)
>   	if (!spin)
>   		return;
>   
> +	pthread_mutex_lock(&list_lock);
>   	igt_list_del(&spin->link);
> +	pthread_mutex_unlock(&list_lock);
>   
>   	if (spin->timer)
>   		timer_delete(spin->timer);
> @@ -297,6 +302,8 @@ void igt_terminate_spin_batches(void)
>   {
>   	struct igt_spin *iter;
>   
> +	pthread_mutex_lock(&list_lock);
>   	igt_list_for_each(iter, &spin_list, link)
>   		igt_spin_batch_end(iter);
> +	pthread_mutex_unlock(&list_lock);
>   }
>