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From: "Hunt, David" <david.hunt@intel.com>
To: Thomas Monjalon <thomas@monjalon.net>,
	"Burakov, Anatoly" <anatoly.burakov@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v1] examples/power: fix oob frequency oscillations
Date: Tue, 29 Oct 2019 14:05:18 +0000	[thread overview]
Message-ID: <0c0b07e4-ef84-056f-bffa-06a402fa99f6@intel.com> (raw)
In-Reply-To: <1655765.anAStuQWUM@xps>


On 27/10/2019 18:35, Thomas Monjalon wrote:
> 06/08/2019 13:18, Thomas Monjalon:
>> 26/07/2019 12:15, Burakov, Anatoly:
>>> So it's biased towards scaling up quickly, but it's doing that over a
>>> period. Please correct me if i'm wrong as i'm not really familiar with
>>> this codebase, but, assuming the window size is long enough, you could
>>> be missing opportunities to scale down? For example, if you get a short
>>> burst of 1's followed by a long burst of zeroes, you're not scaling down
>>> until you go through the entire buffer and overwrite all of the values.
>>> I guess that's the point of oscillation prevention, but maybe you could
>>> improve the "scale-up" part by only checking a few recent values, rather
>>> than the entire buffer?
>> This patch is deferred to 19.11.
> Any news for this patch?
>
The algorithm was intended to be biased (strongly) towards the scale-up, 
for performance reasons. If there is a single "scale-up" in the entire 
array, then we stay up until the entire array agrees that we can scale 
down. If the user wants to relax this, then simply reduce the size of 
the array, which will have the same affect. But I had tested it with an 
array size of 32, and that gave the best results for my use cases.



  reply	other threads:[~2019-10-29 14:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-24 13:18 David Hunt
2019-07-26 10:15 ` Burakov, Anatoly
2019-08-06 11:18   ` Thomas Monjalon
2019-10-27 18:35     ` Thomas Monjalon
2019-10-29 14:05       ` Hunt, David [this message]
2019-11-01 23:00         ` Thomas Monjalon
2019-11-04 10:16           ` Burakov, Anatoly
2019-11-12  7:23 ` [dpdk-dev] [dpdk-stable] " Thomas Monjalon

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