Am 26.01.2018 um
11:22 schrieb Chunming Zhou:
> there is a scheduling balance issue
about get node like:
> a. process A allocates full memory
and use it for submission.
> b. process B tries to allocates
memory, will wait for process A BO idle
in eviction.
> c. process A completes the job,
process B eviction will put process A BO
node,
> but in the meantime, process C is
comming to allocate BO, whill directly
get node successfully, and do
submission,
> process B will again wait for
process C BO idle.
> d. repeat the above setps, process
B could be delayed much more.
>
> later allocation must not be ahead
of front in same place.
Again NAK to the whole approach.
At least with amdgpu the problem you
described above never occurs
because evictions are pipelined
operations. We could only block for
deleted regions to become free.
But independent of that incoming memory
requests while we make room for
eviction are intended to be served
first.
Changing that is certainly a no-go cause
that would favor memory hungry
applications over small clients.
Regards,
Christian.
>
> Change-Id:
I3daa892e50f82226c552cc008a29e55894a98f18
> Signed-off-by: Chunming Zhou
<david1.zhou@xxxxxxx>
> ---
> drivers/gpu/drm/ttm/ttm_bo.c |
69
+++++++++++++++++++++++++++++++++++++++--
> include/drm/ttm/ttm_bo_api.h
| 7 +++++
> include/drm/ttm/ttm_bo_driver.h
| 7 +++++
> 3 files changed, 80
insertions(+), 3 deletions(-)
>
> diff --git
a/drivers/gpu/drm/ttm/ttm_bo.c
b/drivers/gpu/drm/ttm/ttm_bo.c
> index d33a6bb742a1..558ec2cf465d
100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -841,6 +841,58 @@ static int
ttm_bo_add_move_fence(struct
ttm_buffer_object *bo,
> return 0;
> }
>
> +static void
ttm_man_init_waiter(struct ttm_bo_waiter
*waiter,
> +
struct ttm_buffer_object *bo,
> + const
struct ttm_place *place)
> +{
> + waiter->tbo = bo;
> + memcpy((void
*)&waiter->place, (void *)place,
sizeof(*place));
> +
INIT_LIST_HEAD(&waiter->list);
> +}
> +
> +static void
ttm_man_add_waiter(struct
ttm_mem_type_manager *man,
> + struct
ttm_bo_waiter *waiter)
> +{
> + if (!waiter)
> + return;
> +
spin_lock(&man->wait_lock);
> +
list_add_tail(&waiter->list,
&man->waiter_list);
> +
spin_unlock(&man->wait_lock);
> +}
> +
> +static void
ttm_man_del_waiter(struct
ttm_mem_type_manager *man,
> + struct
ttm_bo_waiter *waiter)
> +{
> + if (!waiter)
> + return;
> +
spin_lock(&man->wait_lock);
> + if
(!list_empty(&waiter->list))
> +
list_del(&waiter->list);
> +
spin_unlock(&man->wait_lock);
> + kfree(waiter);
> +}
> +
> +int ttm_man_check_bo(struct
ttm_mem_type_manager *man,
> + struct
ttm_buffer_object *bo,
> + const struct
ttm_place *place)
> +{
> + struct ttm_bo_waiter *waiter,
*tmp;
> +
> +
spin_lock(&man->wait_lock);
> +
list_for_each_entry_safe(waiter, tmp,
&man->waiter_list, list) {
> + if ((bo !=
waiter->tbo) &&
> + ((place->fpfn
>= waiter->place.fpfn &&
> + place->fpfn
<= waiter->place.lpfn) ||
> + (place->lpfn
<= waiter->place.lpfn &&
place->lpfn >=
> +
waiter->place.fpfn)))
> + goto later_bo;
> + }
> +
spin_unlock(&man->wait_lock);
> + return true;
> +later_bo:
> +
spin_unlock(&man->wait_lock);
> + return false;
> +}
> /**
> * Repeatedly evict memory from
the LRU for @mem_type until we create
enough
> * space, or we've evicted
everything and there isn't enough space.
> @@ -853,17 +905,26 @@ static int
ttm_bo_mem_force_space(struct
ttm_buffer_object *bo,
> {
> struct ttm_bo_device *bdev =
bo->bdev;
> struct ttm_mem_type_manager
*man = &bdev->man[mem_type];
> + struct ttm_bo_waiter waiter;
> int ret;
>
> +
ttm_man_init_waiter(&waiter, bo,
place);
> + ttm_man_add_waiter(man,
&waiter);
> do {
> ret =
(*man->func->get_node)(man, bo,
place, mem);
> - if (unlikely(ret !=
0))
> + if (unlikely(ret !=
0)) {
> +
ttm_man_del_waiter(man, &waiter);
> return ret;
> - if (mem->mm_node)
> + }
> + if (mem->mm_node)
{
> +
ttm_man_del_waiter(man, &waiter);
> break;
> + }
> ret =
ttm_mem_evict_first(bdev, mem_type,
place, ctx);
> - if (unlikely(ret !=
0))
> + if (unlikely(ret !=
0)) {
> +
ttm_man_del_waiter(man, &waiter);
> return ret;
> + }
> } while (1);
> mem->mem_type = mem_type;
> return
ttm_bo_add_move_fence(bo, man, mem);
> @@ -1450,6 +1511,8 @@ int
ttm_bo_init_mm(struct ttm_bo_device
*bdev, unsigned type,
> man->use_io_reserve_lru =
false;
>
mutex_init(&man->io_reserve_mutex);
>
spin_lock_init(&man->move_lock);
> +
spin_lock_init(&man->wait_lock);
> +
INIT_LIST_HEAD(&man->waiter_list);
>
INIT_LIST_HEAD(&man->io_reserve_lru);
>
> ret =
bdev->driver->init_mem_type(bdev,
type, man);
> diff --git
a/include/drm/ttm/ttm_bo_api.h
b/include/drm/ttm/ttm_bo_api.h
> index 2cd025c2abe7..0fce4dbd02e7
100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -40,6 +40,7 @@
> #include <linux/mm.h>
> #include <linux/bitmap.h>
> #include
<linux/reservation.h>
> +#include
<drm/ttm/ttm_placement.h>
>
> struct ttm_bo_device;
>
> @@ -232,6 +233,12 @@ struct
ttm_buffer_object {
> struct mutex wu_mutex;
> };
>
> +struct ttm_bo_waiter {
> + struct ttm_buffer_object
*tbo;
> + struct ttm_place place;
> + struct list_head list;
> +};
> +
> /**
> * struct ttm_bo_kmap_obj
> *
> diff --git
a/include/drm/ttm/ttm_bo_driver.h
b/include/drm/ttm/ttm_bo_driver.h
> index 9b417eb2df20..dc6b8b4c9e06
100644
> ---
a/include/drm/ttm/ttm_bo_driver.h
> +++
b/include/drm/ttm/ttm_bo_driver.h
> @@ -293,6 +293,10 @@ struct
ttm_mem_type_manager {
> bool io_reserve_fastpath;
> spinlock_t move_lock;
>
> + /* waiters in list */
> + spinlock_t wait_lock;
> + struct list_head waiter_list;
> +
> /*
> * Protected by
@io_reserve_mutex:
> */
> @@ -748,6 +752,9 @@ int
ttm_bo_mem_space(struct
ttm_buffer_object *bo,
> struct
ttm_mem_reg *mem,
> struct
ttm_operation_ctx *ctx);
>
> +int ttm_man_check_bo(struct
ttm_mem_type_manager *man,
> + struct
ttm_buffer_object *bo,
> + const struct
ttm_place *place);
> void ttm_bo_mem_put(struct
ttm_buffer_object *bo, struct
ttm_mem_reg *mem);
> void ttm_bo_mem_put_locked(struct
ttm_buffer_object *bo,
> struct
ttm_mem_reg *mem);
