On Sun, Jul 06, 2025 at 04:44:27PM -0400, Mario Limonciello wrote:
> On 7/4/2025 6:12 AM, Samuel Zhang wrote:
> > This new api is used for hibernation to move GTT BOs to shmem after
> > VRAM eviction. shmem will be flushed to swap disk later to reduce
> > the system memory usage for hibernation.
> >
> > Signed-off-by: Samuel Zhang <guoqing.zh...@amd.com>
> > ---
> > drivers/gpu/drm/ttm/ttm_device.c | 29 +++++++++++++++++++++++++++++
> > include/drm/ttm/ttm_device.h | 1 +
> > 2 files changed, 30 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_device.c
> > b/drivers/gpu/drm/ttm/ttm_device.c
> > index 02e797fd1891..19ab35ffeead 100644
> > --- a/drivers/gpu/drm/ttm/ttm_device.c
> > +++ b/drivers/gpu/drm/ttm/ttm_device.c
> > @@ -123,6 +123,35 @@ static int ttm_global_init(void)
> > return ret;
> > }
> > +/**
> > + * move GTT BOs to shmem for hibernation.
> > + *
> > + * returns 0 on success, negative on failure.
> > + */
> > +int ttm_device_prepare_hibernation(void)
> > +{
> > + struct ttm_operation_ctx ctx = {
> > + .interruptible = false,
> > + .no_wait_gpu = false,
> > + .force_alloc = true
> > + };
> > + struct ttm_global *glob = &ttm_glob;
> > + struct ttm_device *bdev;
> > + int ret = 0;
> > +
> > + mutex_lock(&ttm_global_mutex);
> > + list_for_each_entry(bdev, &glob->device_list, device_list) {
> > + do {
> > + ret = ttm_device_swapout(bdev, &ctx, GFP_KERNEL);
> > + } while (ret > 0);
> > + if (ret < 0)
> > + break;
> > + }
> > + mutex_unlock(&ttm_global_mutex);
> > + return ret;
>
> I'd personally rather see scoped guard here so you can return immediately
> and the guard will clean up but up to Christian what he thinks.
>
> int ret;
>
> scoped_guard(mutex, &ttm_global_mutex) {
guard(mutex)(&ttm_global_mutex) would be more apporiate for this as the
scope of the guard is the entire function.
Matt
> list_for_each_entry(bdev, &glob->device_list, device_list) {
> do {
> ret = ttm_device_swapout(bdev, &ctx, GFP_KERNEL);
> } while (ret > 0);
> if (ret)
> return ret;
> }
>
> return 0;
>
> > +}
> > +EXPORT_SYMBOL(ttm_device_prepare_hibernation);
> > +
> > /*
> > * A buffer object shrink method that tries to swap out the first
> > * buffer object on the global::swap_lru list.
> > diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
> > index 39b8636b1845..b45498b398dd 100644
> > --- a/include/drm/ttm/ttm_device.h
> > +++ b/include/drm/ttm/ttm_device.h
> > @@ -272,6 +272,7 @@ struct ttm_device {
> > int ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags);
> > int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx
> > *ctx,
> > gfp_t gfp_flags);
> > +int ttm_device_prepare_hibernation(void);
> > static inline struct ttm_resource_manager *
> > ttm_manager_type(struct ttm_device *bdev, int mem_type)
>
