Am 02.07.2016 um 10:39 schrieb Thomas Hellstrom:
Christian,
Thanks for doing this! A question below:
On 06/15/2016 01:44 PM, Christian König wrote:
From: Christian König christian.koenig@amd.com
Free up the memory immediately, remember the last eviction for each domain and make new allocations depend on the last eviction to be completed.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/ttm/ttm_bo.c | 49 ++++++++++++++++++--- drivers/gpu/drm/ttm/ttm_bo_util.c | 92 +++++++++++++++++++++++++++++++++++++++ include/drm/ttm/ttm_bo_driver.h | 24 ++++++++++ 3 files changed, 160 insertions(+), 5 deletions(-)
/* * Protected by @io_reserve_mutex: @@ -298,6 +301,11 @@ struct ttm_mem_type_manager { */
struct list_head lru;
- /*
* Protected by @move_lock.*/- struct fence *move; };
Did you look at protecting the move fence with RCU? I figure where there actually is a fence it doesn't matter much but in the fastpath where move is NULL we'd be able to get rid of a number of locking cycles.
Yeah, thought about that as well.
I guess though there might be both licensing implications and requirements to using kfree_rcu() to free the fence.
The problem wasn't licensing (but it is good that you point that out I wasn't aware of this problem), but that that the existing fence RCU function wouldn't worked here and I didn't had time to take a closer look.
Should be relative easy to switch the read path over, because we already free the fences RCU protected.
Regards, Christian.
/Thomas