Amahi Forums

Posted: **Wed Mar 03, 2010 7:20 pm**

I've noticed that when I'm streaming videos over my wireless network that after a short period of time watching, and/or after transferring a large file from my hda, that the transfers slow significantly (ie., slow transfers or stalled video streaming).

One thing that seems to solve the problem is clearing the cache from my ram using the following:

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sync; echo 3 > /proc/sys/vm/drop_caches

This seems to speed the system right back up, so I don't think it's a network issue. Got the code from here :http://www.scottklarr.com/topic/134/lin ... om-memory/

MY QUESTION IS:

Does anyone know how to insert this into a bash script that would clear the cache when it reaches a certain percentage of ram usage (eg.,50%)? That way I could insert the script at startup and keep my speed all spiffy and shiny like new!!!

Example equation (logic):

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#! /bin/bash
IF="% of cache using ram >/=50%" THEN="sync; echo 3 > /proc/sys/vm/drop_caches"

I know the code is nowhere near correct

but the logic is simple enough.

P.S. I've got plenty of ram (4x1gb) so I'm certain I'm not the only one (at least I think...) that experiences this, plenty of other Amahi users would benefit greatly from a solution to this!!

Posted: **Wed Mar 03, 2010 10:36 pm**

Server-side I'm just opening files from the standard smb shares mounted on desktop thru OSX finder.
Client-side is my Macbook, I'm using VLC 1.0.2 (Intel x64), Quicktime 10.0 (90.3.1).

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VMStat output:
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu-----
 r   b   swpd    free      buff       cache      si   so    bi    bo   in     cs   us sy id  wa st
 0   0     0    516936    39348     2987108       0    0   124     4  244    184   2  1  98   0  0

Posted: **Thu Mar 04, 2010 12:46 am**

hmm not sure about the scripting but what happens if you echo 2 to that parameter?

or like this with the proper command:

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root@host# sysctl -w vm.drop_caches=2

Posted: **Thu Mar 04, 2010 1:23 am**

good point.

this looks weird. we debugged it a bit, but it was not reproducible at the time.

one thing, though, is that the board has ACPI errors in dmesg and has power management enabled. that could be at issue.

other than that, i'm not sure what's going on.

Posted: **Thu Mar 04, 2010 4:44 am**

hmm how is power management defined in the BIOS? APM? ACPI? disabled?

Posted: **Thu Mar 04, 2010 12:53 pm**

power management is defined mainly in ACPI (but also through some cpu registers).

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Script to flush cache in ram?

Script to flush cache in ram?

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Re: Script to flush cache in ram?

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