linux-kernel - Re: odd timing bug with cgroups -- solved

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] [day] [month] [year] [list]

Message-ID: <4856DB4A.8020708@nortel.com>
Date:	Mon, 16 Jun 2008 15:29:46 -0600
From:	"Chris Friesen" <cfriesen@...tel.com>
To:	"Chris Friesen" <cfriesen@...tel.com>
CC:	Valdis.Kletnieks@...edu, linux-kernel@...r.kernel.org,
	vatsa@...ux.vnet.ibm.com, a.p.zijlstra@...llo.nl
Subject: Re: odd timing bug with cgroups -- solved

Chris Friesen wrote:

> I was thinking something like this as well, like maybe we can't move the 
> child to another group until it gets scheduled in once, or something 
> similar.

Well, it appears I was way off base.  My main task is SCHED_RR, and my 
child tasks put themselves into SCHED_OTHER.  I didn't have any realtime 
groups configured, so it was bailing out in the first conditional in 
cpu_cgroup_can_attach().

By also having the parent put the children into SCHED_OTHER, my testcase 
will handle both cases (parent or child runs first) and everything seems 
to be working fine.

Chris
--
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/