Hello, On Thu, Sep 24, 2020 at 01:50:42PM +0200, Peter Zijlstra wrote: > Hurmph.. I suppose you're right :/ And this is an actual problem?
Yeah, this got exposed to userspace as a full 64bit number which overflowed u32 conversion in the rust procfs library which aborted a program I was working on multiple times over several months. On a more theoretical side, it might also surprise nr_iowait_cpu() users. However, a real problem that may be. > I think the below should cure that, but blergh, not nice. If you could > confirm, I'll try and think of something nicer. Rik suggested that it'd be sufficient to return 0 on underflow especially given that 0 is actually the right number to describe the state. So, maybe that can be a nicer code-wise? Thanks. -- tejun
