On 06/18/2012 06:48 AM, Zheng Liu wrote:
> Hi Jens,
>
> I meet a problem when I use ionice(1) to adjust a process's io priority.
> I do the following operations:
>
> $ ionice -p${pid}
> none: prio 0
> $ ionice -p${pid} -c2 -n4
> $ ionice -p${pid}
> best-effort: prio 4
> $ ionice -p${pid} -c0 -n0
> $ ionice -p${pid}
> best-effort: prio 0
>
> So I cannot set scheduling class back to 'none'. If I call ioprio_set(2)
> directly, it will be fine. But if I use ionice(1), I cannot change it. I
> read the docs about ionice in [1]. I notice this code:
>
> switch (ioprio_class) {
> case IOPRIO_CLASS_NONE:
> ioprio_class = IOPRIO_CLASS_BE;
> ^^^^^^^^^^^^^^^^
> *It means that we cannot set back to none.*
> break;
> case IOPRIO_CLASS_RT:
> case IOPRIO_CLASS_BE:
> break;
> case IOPRIO_CLASS_IDLE:
> ioprio = 7;
> break;
> default:
> printf("bad prio class %d\n", ioprio_class);
> return 1;
> }
>
> My question is why we need to ban the user to set back to 'none'. Is there
> some reasons? Thank you.
Since I'm CC'd, I'll explicitly say I haven't a clue why it does this.
Rob
--
GNU/Linux isn't: Linux=GPLv2, GNU=GPLv3+, they can't share code.
Either it's "mere aggregation", or a license violation. Pick one.
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