linux-kernel - Re: [PATCH 2/2] sched: allow users with rtprio rlimit to change from SCHED

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 23 Feb 2011 12:13:54 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Darren Hart <dvhart@...ux.intel.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	richard.purdie@...uxfoundation.org
Subject: Re: [PATCH 2/2] sched: allow users with rtprio rlimit to change from
 SCHED_IDLE policy


* Peter Zijlstra <peterz@...radead.org> wrote:

> On Tue, 2011-02-22 at 13:04 -0800, Darren Hart wrote:
> > As it stands, users with rtprio rlimit permissions can change their policy from
> > SCHED_OTHER to SCHED_FIFO and back. They can change to SCHED_IDLE, but not back
> > to SCHED_FIFO. If they have the rtprio permission, they should be able to. Once
> > in SCHED_FIFO, they could go back to SCHED_OTHER. This patch allows users with
> > rtprio permission to change out of SCHED_IDLE.
> > 
> 
> Ingo, can you remember the rationale for this?
> 
> The fact is that SCHED_IDLE is very near nice-20, and we can do:
> 
> peterz@...ns:~$ renice 5 -p $$
> 1867: old priority 0, new priority 5
> peterz@...ns:~$ renice 0 -p $$
> 1867: old priority 5, new priority 0
> 
> Which would suggest that we should be able to return to SCHED_OTHER
> RLIMIT_NICE-20.

I dont remember anything subtle there - most likely we just forgot about that spot 
when adding RLIMIT_RTPRIO support.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/