When an MMU notifier runs in memory reclaim context, it can deadlock trying to take locks that are already held in the thread causing the memory reclaim. The solution is to avoid memory reclaim while holding locks that are taken in MMU notifiers by using GFP_NOIO.
This commit fixes kmalloc while holding rmn->lock. The GFX MMU notifier also locks reservation objects. I have no good solution for avoiding reclaim while holding reservation objects. The HSA MMU notifier will not lock any reservation objects. Signed-off-by: Felix Kuehling <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c index f2ed18e..b4a5c03 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c @@ -402,7 +402,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr) } if (!node) { - node = kmalloc(sizeof(struct amdgpu_mn_node), GFP_KERNEL); + node = kmalloc(sizeof(struct amdgpu_mn_node), GFP_NOIO); if (!node) { up_write(&rmn->lock); return -ENOMEM; -- 2.7.4 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
