2004-03-01 09:23:13

by Joachim B Haga

[permalink] [raw]
Subject: Re: [RFC][PATCH] O(1) Entitlement Based Scheduler

Peter Williams <[email protected]> writes:

>> It seems to me that much of this could be solved if the user *were*
>> allowed to lower nice values (down to 0).
[snip]
>> to 10 (normal) to 20. Negative values could still be root-only. So
>> why shouldn't this be possible? Because a greedy user in a
>> multi-user system would just run everything at max prio thus
>> defeating the purpose? Sure, that would be annoying but it would
>> have another solution ie. an entitlement based scheduler or
>> something.

> More importantly it would allow ordinary users to override root's
> settings e.g. if (for whatever reason) the sysadmin decided to
> renice a task to 19 (say) this modification would allow the owner of
> the task to renice it back to zero. This is the reason that it
> isn't be allowed.

"You dirty cracker! A renice +19, that'll teach you!" :-)

Seriously though, the same is true today, it's just a bit more
cumbersome. Restart the task and you're back to 0. If the sysadmin
wants to stop that, he'll renice your shell. In which case you login
again. And so on.

My point is that this is a problem (annoying user) which has better
solutions (ranging from a polite e-mail to deluser) because renice
won't stop him.

And it's not a *security* concern, as long as the lower values are
still reserved.

I would say the benefit is very small (I mean: who has ever relied on
it?) compared to the difficulties created for users.


> Peter

Joachim


2004-03-01 10:18:54

by Paul Wagland

[permalink] [raw]
Subject: Re: [RFC][PATCH] O(1) Entitlement Based Scheduler

On Mon, 2004-03-01 at 10:18, Joachim B Haga wrote:
> Peter Williams <[email protected]> writes:
>
> >> It seems to me that much of this could be solved if the user *were*
> >> allowed to lower nice values (down to 0).
> [snip]
> >> to 10 (normal) to 20. Negative values could still be root-only. So
> >> why shouldn't this be possible? Because a greedy user in a
>
> > More importantly it would allow ordinary users to override root's
> > settings e.g. if (for whatever reason) the sysadmin decided to

> And it's not a *security* concern, as long as the lower values are
> still reserved.
>
> I would say the benefit is very small (I mean: who has ever relied on
> it?) compared to the difficulties created for users.

Under Linux, I can't say, but certainly on my old school machine (~10
years ago) all student accounts would run at +5, all staff accounts
would run at +0. This was handled by the login process, so re-logging in
would not help you at all....

Cheers,
Paul

2004-03-01 19:12:37

by Mike Fedyk

[permalink] [raw]
Subject: Re: [RFC][PATCH] O(1) Entitlement Based Scheduler

Paul Wagland wrote:
> On Mon, 2004-03-01 at 10:18, Joachim B Haga wrote:
>
>>Peter Williams <[email protected]> writes:
>>
>>
>>>>It seems to me that much of this could be solved if the user *were*
>>>>allowed to lower nice values (down to 0).
>>
>>[snip]
>>
>>>>to 10 (normal) to 20. Negative values could still be root-only. So
>>>>why shouldn't this be possible? Because a greedy user in a
>>
>>
>>
>>>More importantly it would allow ordinary users to override root's
>>>settings e.g. if (for whatever reason) the sysadmin decided to
>
>
>>And it's not a *security* concern, as long as the lower values are
>>still reserved.
>>
>>I would say the benefit is very small (I mean: who has ever relied on
>>it?) compared to the difficulties created for users.
>
>
> Under Linux, I can't say, but certainly on my old school machine (~10
> years ago) all student accounts would run at +5, all staff accounts
> would run at +0. This was handled by the login process, so re-logging in
> would not help you at all....

I think you can do this with pam or login under linux. I know I did
something like this, but since most of my users were samba users, it
wasn't very useful at the time