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From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: "Linus Lüssing" <linus.luessing@c0d3.blue>,
	"Marek Lindner" <mareklindner@neomailbox.ch>
Subject: Re: [B.A.T.M.A.N.] [PATCH v2 6/7] batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available
Date: Mon, 21 May 2018 19:51:49 +0200	[thread overview]
Message-ID: <1559212.ar4OgO3PtD@sven-edge> (raw)
In-Reply-To: <20180521131711.GK7162@otheros>

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On Montag, 21. Mai 2018 15:17:11 CEST Linus Lüssing wrote:
> What is the advantage of using the ilog2 and shift operator here
> compared to plain multiplications and divisions?

They most likely ran into the problem that they must do a 64 bit division 
(which cannot be done on 32 bit machines in the kernel directly with C's 
native "x / y" statement ). But in this case, it is most likely a lot better 
to use do_div (or similar function) to avoid a lot of rounding problems which 
this shift approach has.

Kind regards,
	Sven

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  reply	other threads:[~2018-05-21 17:51 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-18  1:47 [B.A.T.M.A.N.] [PATCH v2 0/7] B.A.T.M.A.N. V - fallback to tp meter estimation if throughput otherwise not available Marek Lindner
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 1/7] batman-adv: tp_meter - prevent concurrent tp_meter sessions by using workqueue Marek Lindner
2018-08-29  6:56   ` Sven Eckelmann
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 2/7] batman-adv: tp_meter - don't check for existing session Marek Lindner
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 3/7] batman-adv: tp_meter - allow up to 10 queued sessions Marek Lindner
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 4/7] batman-adv: tp_meter - add caller distinction Marek Lindner
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 5/7] batman-adv: tp_meter - add option to perform one-hop test Marek Lindner
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 6/7] batman-adv: ELP - use tp meter to estimate the throughput if otherwise not available Marek Lindner
2018-05-21 13:17   ` Linus Lüssing
2018-05-21 17:51     ` Sven Eckelmann [this message]
2018-05-21 19:06     ` Sven Eckelmann
2018-08-04  9:31       ` Antonio Quartulli
2018-05-21 14:43   ` Linus Lüssing
2018-08-04  9:35     ` Marek Lindner
2018-05-21 14:48   ` Linus Lüssing
2018-08-04  9:39     ` Antonio Quartulli
2018-05-21 15:01   ` Linus Lüssing
2018-08-04  8:59     ` Antonio Quartulli
2018-05-21 16:36   ` Sven Eckelmann
2018-05-18  1:47 ` [B.A.T.M.A.N.] [PATCH v2 7/7] batman-adv: ELP - add throughput meter test duration attribute Marek Lindner
2018-05-21 13:46   ` Linus Lüssing
2018-05-21 13:57     ` Linus Lüssing
2018-08-04  9:05     ` Marek Lindner
2018-05-21 14:34   ` Sven Eckelmann
2018-08-04  8:41     ` Antonio Quartulli
     [not found]       ` <314bf0ac-4c10-da7a-d527-45afe92423fa-2CpIooy/SPIKlTDg6p0iyA@public.gmane.org>
2018-08-04  9:02         ` Sven Eckelmann
2018-08-04  9:02           ` [B.A.T.M.A.N.] " Sven Eckelmann
2018-08-04  9:08           ` Antonio Quartulli
2018-08-04  9:08             ` [B.A.T.M.A.N.] " Antonio Quartulli

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