Re: [Jack-Devel] Everything works with JACK, but I always got "Cannot lock down ..." message at startup

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DateWed, 05 Dec 2012 17:06:03 +0200
From Stefan Stefanov <[hidden] at gmail dot com>
ToAdrian Knoth <[hidden] at drcomp dot erfurt dot thur dot de>
CcJACK <[hidden] at lists dot jackaudio dot org>
In-Reply-ToAdrian Knoth Re: [Jack-Devel] Everything works with JACK, but I always got "Cannot lock down ..." message at startup
Follow-UpStefan Stefanov Re: [Jack-Devel] Everything works with JACK, but I always got "Cannot lock down ..." message at startup
Thanks:)

BTW, you were right - it was systemd related.
"Cannot lock down ..." message doesn't appear any more after applying
scheduling policies in jack.service unit:

 [Unit]
Description=JACK
After=sound.target

[Service]
User=stefan
ExecStart=/usr/bin/jackd -R -P 95 -d alsa -P hw:0,1 -r 96000 -p 64 -n 2 -z s
CPUSchedulingPriority=95
CPUSchedulingPolicy=rr
MemoryLimit=512M
MemorySoftLimit=512M
LimitRTPRIO=infinity
LimitRTTIME=infinity
LimitMEMLOCK=infinity

[Install]
WantedBy=multi-user.target

I will follow your advice about increasing a bit the latency :)

2012/12/5 Adrian Knoth <[hidden]>:
> On Wed, Dec 05, 2012 at 03:59:35PM +0200, Stefan Stefanov wrote:
>
>> >-P 95 seems pretty high
>> BTW, having in mind my equipment what would be reasonable priority value?
>
> Stick to the defaults, so simply omit the -P 95 altogether.
>
> I would probably raise the latency (your -p 64) to the defaults (1024)
> or even higher. 20ms latency (-p 2048 at 96kHz) are perfectly fine for
> subsequent volume adjustments and would considerably lower the CPU's
> stress level. ;)
>
>
> Cheers
>
> --
> mail: [hidden]       http://adi.thur.de      PGP/GPG: key via keyserver
>
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