linux-kernel - Re: [BUG] cpu-hotplug: Can't offline the CPU with naughty realtime processes

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]

Message-Id: <1178593345.28438.29.camel@localhost.localdomain>
Date:	Tue, 08 May 2007 13:02:25 +1000
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	Satoru Takeuchi <takeuchi_satoru@...fujitsu.com>
Cc:	Linux Kernel <linux-kernel@...r.kernel.org>,
	Srivatsa Vaddagiri <vatsa@...ibm.com>,
	Zwane Mwaikambo <zwane@....linux.org.uk>,
	Nathan Lynch <nathanl@...tin.ibm.com>,
	Joel Schopp <jschopp@...tin.ibm.com>,
	Ashok Raj <ashok.raj@...el.com>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	Gautham R Shenoy <ego@...ibm.com>
Subject: Re: [BUG] cpu-hotplug: Can't offline the CPU with naughty
	realtime	processes

On Tue, 2007-05-08 at 11:41 +0900, Satoru Takeuchi wrote:
> At Mon, 07 May 2007 23:42:53 +1000,
> Rusty Russell wrote:
> > I look forward to your patch!
> > Rusty.
> 
> Thanks, I'll do. Maybe this work will take several days including test.

Excellent.

> BTW, how should I manage rt process having max priority as Gautham said?
> He said that it's OK unless such kernel thread exists. However, currently
> MAX_USER_RT_PRIORITY is equal to MAX_RT_PRIO, so user process also be able
> to cause this problem. Is Srivatsa's idea 2 acceptable? Or just apply
> "Shouldn't abuse highest rt proority" rule?

We used to be able to create kernel threads higher than any userspace
priority.  If this is no longer true, I think that's OK: equal priority
still means we'll get scheduled, right?

Cheers,
Rusty.


-
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/