linux-kernel - Re: [Priority Inheritance] SCHED_FIFO or 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:	Fri, 30 Sep 2011 21:12:58 +0200
From:	"Tadeus (Eus) Prastowo" <0x657573@...glemail.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: [Priority Inheritance] SCHED_FIFO or SCHED_RR?

Anyone familiar with the Linux scheduler, please?

On Wed, Sep 28, 2011 at 1:06 AM, Tadeus (Eus) Prastowo
<0x657573@...glemail.com> wrote:
> Hi!
>
> When a SCHED_RR task with RT priority X blocks on a
> priority-inheriting mutex held by a SCHED_NORMAL task with nice value
> Y, RT-Mutex code will change the SCHED_NORMAL task priority to that of
> the SCHED_RR task and based on the new priority, will change the
> scheduling class too. But, each task retains its own scheduling
> policy.
>
> This means that the task inheriting the SCHED_RR priority will be
> scheduled using SCHED_FIFO policy because task_tick_rt does not
> enforce the SCHED_RR time slice when the task policy is not SCHED_RR.
>
> Why should a SCHED_NORMAL task inheriting the priority of a SCHED_RR
> task get the privilege of SCHED_FIFO task for running as long as it
> wishes even when the task giving the inheritance does not have such
> privilege?
>
> Thank you very much.
>
> Please kindly put me in the CC since I am not subscribed to the list.
>
> --
> Eus
--
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/