linux-kernel - Re: [patch 11/15] sched: prevent interactions between throttled entities and load-balance

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:	Tue, 10 May 2011 16:26:50 +0900
From:	Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>
To:	Paul Turner <pjt@...gle.com>
CC:	linux-kernel@...r.kernel.org,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Bharata B Rao <bharata@...ux.vnet.ibm.com>,
	Dhaval Giani <dhaval.giani@...il.com>,
	Balbir Singh <balbir@...ux.vnet.ibm.com>,
	Vaidyanathan Srinivasan <svaidy@...ux.vnet.ibm.com>,
	Srivatsa Vaddagiri <vatsa@...ibm.com>,
	Kamalesh Babulal <kamalesh@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...e.hu>, Pavel Emelyanov <xemul@...nvz.org>
Subject: Re: [patch 11/15] sched: prevent interactions between throttled entities
 and load-balance

(2011/05/03 18:28), Paul Turner wrote:
>>>From the perspective of load-balance and shares distribution, throttled
> entities should be invisible.
> 
> However, both of these operations work on 'active' lists and are not
> inherently aware of what group hierarchies may be present.  In some cases this
> may be side-stepped (e.g. we could sideload via tg_load_down in load balance) 
> while in others (e.g. update_shares()) it is more difficult to compute without
> incurring some O(n^2) costs.
> 
> Instead, track hierarchal throttled state at time of transition.  This allows

                 hierarchical

> us to easily identify whether an entity belongs to a throttled hierarchy and
> avoid incorrect interactions with it.
> 
> Also, when an entity leaves a throttled hierarchy we need to advance its
> time averaging for shares averaging so that the elapsed throttled time is not
> considered as part of the cfs_rq's operation.
> 
> Signed-off-by: Paul Turner <pjt@...gle.com>
> ---

Reviewed-by: Hidetoshi Seto <seto.hidetoshi@...fujitsu.com>

Thanks,
H.Seto

--
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/