linux-kernel - Re: [BUG] sched: fair group's bug

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:	Thu, 08 Jan 2009 15:16:35 +0100
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	miaox@...fujitsu.com
Cc:	Ingo Molnar <mingo@...e.hu>,
	Linux-Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [BUG] sched: fair group's bug

On Thu, 2009-01-08 at 09:30 +0800, Miao Xie wrote:
> I tested fair group scheduler on my hyper-threading x86_64 box(2 CPU * 2 HT)
> and found the deviation of the groups' CPU usage was larger than 2.6.26
> when *offline* a CPU or do hotplug frequently. It is less than 1% On 2.6.26，but
> On current kernel, it is often greater than 4%, even than 10% by accident.

Its not a bug -- a scheduler without smp awareness cannot be compared to
one without -- .26 just wasn't a complete group scheduler.

At best its a regression for your particular workload.

--
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/