linux-kernel - Re: [PATCH 12/14] sched: make dl_bw a sub-quota of rt

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: <525D289C.1020402@gmail.com>
Date:	Tue, 15 Oct 2013 13:35:56 +0200
From:	Juri Lelli <juri.lelli@...il.com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	Ingo Molnar <mingo@...nel.org>, tglx@...utronix.de,
	mingo@...hat.com, rostedt@...dmis.org, oleg@...hat.com,
	fweisbec@...il.com, darren@...art.com, johan.eker@...csson.com,
	p.faure@...tech.ch, linux-kernel@...r.kernel.org,
	claudio@...dence.eu.com, michael@...rulasolutions.com,
	fchecconi@...il.com, tommaso.cucinotta@...up.it,
	nicola.manica@...i.unitn.it, luca.abeni@...tn.it,
	dhaval.giani@...il.com, hgu1972@...il.com,
	paulmck@...ux.vnet.ibm.com, raistlin@...ux.it,
	insop.song@...il.com, liming.wang@...driver.com, jkacur@...hat.com,
	harald.gustafsson@...csson.com, vincent.guittot@...aro.org,
	bruce.ashfield@...driver.com--no-chain-reply-to
Subject: Re: [PATCH 12/14] sched: make dl_bw a sub-quota of rt_bw

On 10/15/2013 12:26 PM, Peter Zijlstra wrote:
> On Tue, Oct 15, 2013 at 12:00:20PM +0200, Juri Lelli wrote:
>> On 10/14/2013 04:06 PM, Ingo Molnar wrote:
>>>
>>> * Juri Lelli <juri.lelli@...il.com> wrote:
>>>
>>>> +#ifdef CONFIG_SMP
>>>> +		struct dl_bw *dl_b = &cpu_rq(i)->rd->dl_bw;
>>>> +#else
>>>> +		struct dl_bw *dl_b = &cpu_rq(i)->dl.dl_bw;
>>>> +#endif
>>>
>>>> +#ifdef CONFIG_SMP
>>>> +		struct dl_bw *dl_b = &cpu_rq(i)->rd->dl_bw;
>>>> +#else
>>>> +		struct dl_bw *dl_b = &cpu_rq(i)->dl.dl_bw;
>>>> +#endif
>>>
>>> Btw., this kind of SMP/UP assymetry pattern really sucks. Why not make UP 
>>> use the SMP data structure, even if it's degenerate?
>>>
>>
>> Yes, I don't like it either, but that comes from the fact that it seemed to me
>> that, semantically, bandwidth for -deadline tasks has to be associated to the
>> single runqueue in UP and to the root_domain for SMP. In UP root_domain is
>> compiled out, so I'm not sure to understand what you suggest. I could probably
>> let dl_bw live on runqueues with the assumption that all the runqueues from the
>> same root_domain have the same dl_bw, that represents the dl_bw of the
>> root_domain. But I don't like this replication either :(.
> 
> #ifdef CONFIG_SMP
> 
> static inline struct dl_bw *dl_bw_of(int i)
> {
> 	return &cpu_rq(i)->rd->dl_bw;
> }
> 
> #else
> 
> static inline struct dl_bw *dl_bw_of(int i)
> {
> 	return &cpu_rq(i)->dl.dl_bw;
> }
> 
> #endif
> 
> ?
> 

Yes, way better.

Thanks,

- Juri
--
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/