linux-kernel - Re: [-mm] Add an owner to the mm

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: <47F5266B.2060402@linux.vnet.ibm.com>
Date:	Fri, 04 Apr 2008 00:18:11 +0530
From:	Balbir Singh <balbir@...ux.vnet.ibm.com>
To:	Paul Menage <menage@...gle.com>
CC:	Pavel Emelianov <xemul@...nvz.org>,
	Hugh Dickins <hugh@...itas.com>,
	Sudhir Kumar <skumar@...ux.vnet.ibm.com>,
	YAMAMOTO Takashi <yamamoto@...inux.co.jp>, lizf@...fujitsu.com,
	linux-kernel@...r.kernel.org, taka@...inux.co.jp,
	linux-mm@...ck.org, David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Subject: Re: [-mm] Add an owner to the mm_struct (v7)

Paul Menage wrote:
> On Thu, Apr 3, 2008 at 11:34 AM, Balbir Singh <balbir@...ux.vnet.ibm.com> wrote:
>>  That is indeed quite bad. Do we have to retire the group_leader to init_css_set?
>>  Can we not check for delay_group_leader() there?
>>
> 
> That might have unintentded consequences, such as leaving a pid in the
> cgroup that can't be moved (since it's PF_EXITING) but won't go away
> until its threads have all exited.
> Maybe that's OK if the other threads are guaranteed to have started
> exiting by this point. We'd need some cleanup for when the group
> leader finally did exit.

Yes, we might be stuck with an unremovable group, but I am not sure how to
address the side-effect at this point. Not having that check could mean that
mm_update_new_owner() will be called very frequently and for thousands of
threads that could clearly become an overhead, if threads start exiting one by
one - lead by the thread group leader.

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL
--
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/