linux-kernel - Re: [PATCH] sched/numa: Restore sched feature NUMA to its earlier avatar.

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: <20150708135644.GC23380@gmail.com>
Date:	Wed, 8 Jul 2015 15:56:45 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel@...r.kernel.org, Rik van Riel <riel@...hat.com>,
	Mel Gorman <mgorman@...e.de>
Subject: Re: [PATCH] sched/numa: Restore sched feature NUMA to its earlier
 avatar.


* Srikar Dronamraju <srikar@...ux.vnet.ibm.com> wrote:

> In commit:8a9e62a "sched/numa: Prefer NUMA hotness over cache hotness"
> sched feature NUMA was always set to true. However this sched feature was
> suppose to be enabled on NUMA boxes only thro set_numabalancing_state().
>
> To get back to the above behaviour, bring back NUMA_FAVOUR_HIGHER feature.

Three typos and a non-standard commit ID reference.

>  /*
> + * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a
> + * higher number of hinting faults are recorded during active load
> + * balancing. It will resist moving tasks towards nodes where a lower
> + * number of hinting faults have been recorded.
>   */
> -SCHED_FEAT(NUMA,	true)
> +SCHED_FEAT(NUMA_FAVOUR_HIGHER, true)
>  #endif
> 

So the comment spells 'favor' American, the constant you introduce is British 
spelling via 'FAVOUR'? Please use it consistently!

Also, this name is totally non-intuitive.

Make it something like NUMA_FAVOR_BUSY_NODES or so?

Also, I'm wondering how this can schedule in a stable fashion: if a non-busy node 
is not favored, how can we end up there to start building up hinting faults?

Thanks,

	Ingo
--
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/