Tensor not dropped after another tensor was assigned to variable in cuda

[daguix]

Hello,

When I execute this code

`let tensor1 = Tensor::randn(0f32, 1f32, &[1024,1024,1024], &gpu)?;

let tensor1 = candle_nn::ops::softmax_last_dim(&tensor1)?;

let tensor2 = Tensor::randn(0f32, 1f32, &[1024,1024,1024], &gpu)?;`

It takes 12GB of VRAM instead of 8GB. It runs into OOM error in cuda. The old tensor1 is not dropped in second line.

Meanwhile with this code:

`let tensor1 = Tensor::randn(0f32, 1f32, &[1024,1024,1024], &gpu)?;

let tensor2 = candle_nn::ops::softmax_last_dim(&tensor1)?;

drop(tensor1);

let tensor3 = Tensor::randn(0f32, 1f32, &[1024,1024,1024], &gpu)?;`

the memory is correctly cleaned.

[daguix]

Same with cpu btw

[Laurent Mazare]

That's not really specific to candle but rather a rust behavior: variables only get dropped at the end of the scope (it also applies to mutex guards and all other RAII use cases).

[daguix]

Erf I misunderstood shadowing in rust. My bad. Thanks.