linux-kernel - Re: [PATCH 0/2] sched: tasklist_lock cleanups (Was: don't use while_each

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: <20140818150916.GA19364@redhat.com>
Date:	Mon, 18 Aug 2014 17:09:16 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Kirill Tkhai <tkhai@...dex.ru>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Rik van Riel <riel@...hat.com>,
	Mike Galbraith <umgwanakikbuti@...il.com>,
	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>,
	Frank Mayhar <fmayhar@...gle.com>,
	Frederic Weisbecker <fweisbec@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Sanjay Rao <srao@...hat.com>,
	Larry Woodman <lwoodman@...hat.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/2] sched: tasklist_lock cleanups (Was: don't use
	while_each_thread())

On 08/18, Kirill Tkhai wrote:
>
> On 17.08.2014 19:25, Oleg Nesterov wrote:
> >
> > And I can't understand tg_has_rt_tasks(). Don't we need something
> > like the patch below? If not, please do not ask me why I think so,
> > I don't understand this black magic ;) But the usage of the global
> > "runqueues" array looks suspicious.
>
> This function searches RT task which is related to this tg. It's
> opaquely because it looks that there is an error.
>
> task_rq(p)->rt.tg is a task group of a top rt_rq, while the task may
> be queued on a child rt_rq instead of this. So, your patch is a BUGFIX,
> not a cleanup.

Yes, thanks, this was my (vague) understanding. But since I don't know
even the terminology I wasn't able to explain my concerns.

OK, I am going to shamelessly steal your words and turn them into the
changelog.

Thanks.

Oleg.

--
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/