Hi Jeanette, On 2019-08-05 19:19:34 (+0200), Jeanette C. wrote: > JACK has long had a habit of grabbing a lot of CPU time, even in idel > mode, getting to 100% (one of four cores) and raising the CPU from > 800MHz to 3GHz. How do you start jack? At what samplerate/buffersize? Is it the same with jack2? You can also check what's going on in iotop. Not sure how easy that is to use for you, but at least it's a CLI tool (and has a man page!). > I have set the kernel commandline parameter audit=0 . It's not necessarily *that* performance degrading, but YMMV. > Another suggestion recommended trying something with spectre mitigation. Please don't attempt that, unless you won't be connected to the internet. ;-) > Can someone please help me through this? Hints, tips, maybe similar > experiences and good solutions? I've also had some degrading performance issues with my Lenovo W540 starting with linux > 5.0. Guess it's a mixture of Intel mitigations and ucode updates. Yay :-/ You can try with linux-rt and/or linux-rt-lts. They're now pre-compiled in an unofficial repository [1]. As I build/signed these, you won't have to import a key or anything, but merely add the additional entry to /etc/pacman.conf [2]. > I have run: > realTimeConfigQuickScan > which aggreed with everything except that my kernel isn't real > lowlatency. > It's the standard pacman kernel. And it didn't like the schedutil > governor, which I change to performance, when I'm recording. Do you use irqbalance? This could help in distributing the (hardware) Interrupt Request (IRQ) handling on your system over your various cores/threads. > More info? > CPU: AMD Athlon(tm) II X4 640 Processor (/proc/cpuinfo) > quadcore with up to 3GHz > 4GB of RAM (mostly no issues at all) That's not a superlot of RAM, but you also don't have any hungry GUIs :-) Do you use amd-ucode? Which bootloader do you use? > Soundcard: twl M-Audio Delta 1010LT sync'ed by SP/DIF and bundled into > one device through ALSA through multi device type. So, you're saying, that you're using two soundcards? That could in theory be a problem (at least to performance). As you're not using a realtime kernel currently, I assume, you're also not using something to tune your IRQs (e.g. rtirq). However, that could be quite interesting for boosting the performance. It requires you to figure out, whether you have IRQs, that are shared: ``` cat /proc/interrupts |grep ", " ``` and whether those are somehow related to the hardware you would like to use (e.g. your builtin soundcard). Those devices (names are in the last column), can be boosted to a higher RTPRIO using rtirq. The wiki articles about most of this are still lacking big time IMHO... if I find time in the coming weeks, I'll try to improve them. I hope this got you some ideas where to look and what to try nonetheless. Best, David [1] https://wiki.archlinux.org/index.php/Unofficial_user_repositories#dvzrv [2] https://wiki.archlinux.org/index.php/Pacman#Repositories_and_mirrors -- https://sleepmap.de
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