[PATCH 02/11] drm/ttm: add common accounting to the resource mgr v3

[Matthew Auld]

On Mon, 14 Feb 2022 at 13:23, Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 14.02.22 um 11:34 schrieb Matthew Auld:
> > On Mon, 14 Feb 2022 at 09:34, Christian König
> > <ckoenig.leichtzumerken at gmail.com> wrote:
> >> It makes sense to have this in the common manager for debugging and
> >> accounting of how much resources are used.
> >>
> >> v2: cleanup kerneldoc a bit
> >> v3: drop the atomic, update counter under lock instead
> >>
> >> Signed-off-by: Christian König <christian.koenig at amd.com>
> >> Reviewed-by: Huang Rui <ray.huang at amd.com> (v1)
> >> Tested-by: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
> >> ---
> >>   drivers/gpu/drm/ttm/ttm_resource.c | 30 ++++++++++++++++++++++++++++++
> >>   include/drm/ttm/ttm_resource.h     | 11 +++++++++--
> >>   2 files changed, 39 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
> >> index ae40e144e728..bbb8a0f7aa14 100644
> >> --- a/drivers/gpu/drm/ttm/ttm_resource.c
> >> +++ b/drivers/gpu/drm/ttm/ttm_resource.c
> >> @@ -41,6 +41,8 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
> >>                          const struct ttm_place *place,
> >>                          struct ttm_resource *res)
> >>   {
> >> +       struct ttm_resource_manager *man;
> >> +
> >>          res->start = 0;
> >>          res->num_pages = PFN_UP(bo->base.size);
> >>          res->mem_type = place->mem_type;
> >> @@ -50,6 +52,11 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
> >>          res->bus.is_iomem = false;
> >>          res->bus.caching = ttm_cached;
> >>          res->bo = bo;
> >> +
> >> +       man = ttm_manager_type(bo->bdev, place->mem_type);
> >> +       spin_lock(&bo->bdev->lru_lock);
> >> +       man->usage += bo->base.size;
> >> +       spin_unlock(&bo->bdev->lru_lock);
> >>   }
> >>   EXPORT_SYMBOL(ttm_resource_init);
> >>
> >> @@ -65,6 +72,9 @@ EXPORT_SYMBOL(ttm_resource_init);
> >>   void ttm_resource_fini(struct ttm_resource_manager *man,
> >>                         struct ttm_resource *res)
> >>   {
> >> +       spin_lock(&man->bdev->lru_lock);
> >> +       man->usage -= res->bo->base.size;
> >> +       spin_unlock(&man->bdev->lru_lock);
> >>   }
> >>   EXPORT_SYMBOL(ttm_resource_fini);
> >>
> >> @@ -166,6 +176,7 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
> >>          spin_lock_init(&man->move_lock);
> >>          man->bdev = bdev;
> >>          man->size = size;
> >> +       man->usage = 0;
> >>
> >>          for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
> >>                  INIT_LIST_HEAD(&man->lru[i]);
> >> @@ -226,6 +237,24 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
> >>   }
> >>   EXPORT_SYMBOL(ttm_resource_manager_evict_all);
> >>
> >> +/**
> >> + * ttm_resource_manager_usage
> >> + *
> >> + * @man: A memory manager object.
> >> + *
> >> + * Return how many resources are currently used.
> > Maybe mention the units here?
> >
> > "Return how many resources are currently used, in bytes."
>
> Well exactly that's not correct. The whole idea here is that these are
> driver defined units.

Ok, I was assuming bo->base.size to operate in bytes(the kernel-doc
seems to indicate that) and ttm_resource_{init, fini} are using this
to track the man->usage.

>
> E.g. for the AMDGPU OA and GWS resources it's essentially a hardware block.
>
> Regards,
> Christian.
>
> >
> > Anyway,
> > Reviewed-by: Matthew Auld <matthew.auld at intel.com>
> >
> >> + */
> >> +uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man)
> >> +{
> >> +       uint64_t usage;
> >> +
> >> +       spin_lock(&man->bdev->lru_lock);
> >> +       usage = man->usage;
> >> +       spin_unlock(&man->bdev->lru_lock);
> >> +       return usage;
> >> +}
> >> +EXPORT_SYMBOL(ttm_resource_manager_usage);
> >> +
> >>   /**
> >>    * ttm_resource_manager_debug
> >>    *
> >> @@ -238,6 +267,7 @@ void ttm_resource_manager_debug(struct ttm_resource_manager *man,
> >>          drm_printf(p, "  use_type: %d\n", man->use_type);
> >>          drm_printf(p, "  use_tt: %d\n", man->use_tt);
> >>          drm_printf(p, "  size: %llu\n", man->size);
> >> +       drm_printf(p, "  usage: %llu\n", ttm_resource_manager_usage(man));
> >>          if (man->func->debug)
> >>                  man->func->debug(man, p);
> >>   }
> >> diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
> >> index 555a11fb8a7f..323c14a30c6b 100644
> >> --- a/include/drm/ttm/ttm_resource.h
> >> +++ b/include/drm/ttm/ttm_resource.h
> >> @@ -27,6 +27,7 @@
> >>
> >>   #include <linux/types.h>
> >>   #include <linux/mutex.h>
> >> +#include <linux/atomic.h>
> >>   #include <linux/dma-buf-map.h>
> >>   #include <linux/dma-fence.h>
> >>   #include <drm/drm_print.h>
> >> @@ -130,10 +131,15 @@ struct ttm_resource_manager {
> >>          struct dma_fence *move;
> >>
> >>          /*
> >> -        * Protected by the global->lru_lock.
> >> +        * Protected by the bdev->lru_lock.
> >>           */
> >> -
> >>          struct list_head lru[TTM_MAX_BO_PRIORITY];
> >> +
> >> +       /**
> >> +        * @usage: How much of the resources are used, protected by the
> >> +        * bdev->lru_lock.
> >> +        */
> >> +       uint64_t usage;
> >>   };
> >>
> >>   /**
> >> @@ -283,6 +289,7 @@ void ttm_resource_manager_init(struct ttm_resource_manager *man,
> >>   int ttm_resource_manager_evict_all(struct ttm_device *bdev,
> >>                                     struct ttm_resource_manager *man);
> >>
> >> +uint64_t ttm_resource_manager_usage(struct ttm_resource_manager *man);
> >>   void ttm_resource_manager_debug(struct ttm_resource_manager *man,
> >>                                  struct drm_printer *p);
> >>
> >> --
> >> 2.25.1
> >>
>