Re: [PATCH] blk-throttle: Calculate allowed value only when the throttle is enabled

From: Oleg Nesterov
Date: Thu Oct 05 2023 - 13:15:56 EST


sorry, didn't notice this part before.

I am not a asm expert (to say at least;) but

On 10/05, Li Nan wrote:
>
> When (a * mul) overflows, a divide 0 error occurs in
> mul_u64_u64_div_u64().

Just in case... No, iirc it is divq which triggers #DE when the
result of division doesn't fit u64.

(a * mul) can't overflow, the result is 128-bit rax:rdx number.

Oleg.