Re: [Intel-xe] [PATCH 1/2] drm/xe: Make page-table updates using the default engine happen in order

[Matthew Brost <matthew.brost@intel.com>]

On Thu, Jun 29, 2023 at 10:51:33PM +0200, Thomas Hellström wrote:
> If the default engine m->eng was used, there is no check for idle and
> a cpu page-table update may thus happen in parallel with a gpu one.
> Don't allow CPU page-table updates with the default engine until
> the engine is idle.
> 
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_migrate.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
> index 55e113dd7e82..41c90f6710ee 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.c
> +++ b/drivers/gpu/drm/xe/xe_migrate.c
> @@ -1160,9 +1160,10 @@ xe_migrate_update_pgtables(struct xe_migrate *m,
>  	int err = 0;
>  	bool usm = !eng && xe->info.supports_usm;
>  	bool first_munmap_rebind = vma && vma->first_munmap_rebind;
> +	struct xe_engine *eng_override = !eng ? m->eng : eng;
>  
>  	/* Use the CPU if no in syncs and engine is idle */
> -	if (no_in_syncs(syncs, num_syncs) && (!eng || xe_engine_is_idle(eng))) {
> +	if (no_in_syncs(syncs, num_syncs) && xe_engine_is_idle(eng_override)) {
>  		fence =  xe_migrate_update_pgtables_cpu(m, vm, bo, updates,
>  							num_updates,
>  							first_munmap_rebind,
> -- 
> 2.40.1
>