On 11 October 2012 at 9:07, Jeremy Jongepier <jeremy@xxxxxxxxxxxxxx> wrote: > On 10/11/2012 08:33 AM, Kevin Cosgrove wrote: > > > >> More information on tweaking your setup: > >> http://wiki.linuxmusicians.com/doku.php?id=system_configuration > > > > I've been trying to reduce my xrun troubles. I'm down from > 10 > > xruns per second to something more like 10 xruns per minute. Still > > not good, but better. > > > > I used the realTimeConfigQuickScan.pl script to diagnose things. > > > > https://code.google.com/p/realtimeconfigquickscan/ > > > > I'm down to three things reported as "not good" now. > > > > 1. Checking checking sysctl inotify max_user_watches... < 524288 - not good > > increase max_user_watches by adding 'fs.inotify.max_user_watches = 524288' > > to /etc/sysctl.conf and rebooting > > For more information, see > > http://wiki.linuxmusicians.com/doku.php?id=system_configuration#sysctl.conf > > > > Looking at the link there's a comment, "...it remains very > > unclear ... if adjusting this value actually does anything at > > all." So, I haven't altered this. Does anyone have > > experience saying that this helped them? > > > > Hello Kevin, > > I've added this comment after having asked the exact same question at my > LAC2011 workshop. Nobody in the audience could acknowledge that changing > the inotify setting helped anything. Nice to know. > > 2. chrt: failed to set pid 0's policy: Operation not permitted > > Checking the ability to prioritize processes with chrt... no - not good > > Could not assign a 80 rtprio value. Set up limits.conf. > > For more information, see > > http://wiki.linuxmusicians.com/doku.php?id=system_configuration#limits.conf > > > > I did make the changes outlined at the above link. I still > > get the above report. I'm going to guess that I need some > > real-time support from the kernel to make this work. Which > > brings me to > > > > 3. Kernel with Real-Time Preemption... not found - not good > > Kernel without real-time capabilities found > > For more information, see > > http://wiki.linuxmusicians.com/doku.php?id=system_configuration#installing_a_real-time_kernel > > > > First I looked at this link: > > http://wiki.linuxmusicians.com/doku.php?id=system_configuration#the_kernel > > Specifically, I looked at the threadirqs kernel option. > > > > grep -e CONFIG_IRQ_FORCED_THREADING=y -e CONFIG_PREEMPT=y /boot/config-`uname -r` > > produces "CONFIG_IRQ_FORCED_THREADING=y" and I think that's good. > > > > No it's not, unless it also outputs CONFIG_PREEMPT=y. if it doesn't than > your kernel isn't preemtible and in that case I doubt if threadirqs or > even chrt works (no expert on this). A comment at the above link says, "If [the grep command] returns CONFIG_IRQ_FORCED_THREADING=y and CONFIG_PREEMPT=y then your kernel is using IRQ threading and you don't have to proceed with the following steps. If it only returns CONFIG_IRQ_FORCED_THREADING=y you can add the threadirqs boot option as described..." My grep was in the 2nd case, with only CONFIG_IRQ_FORCED_THREADING set to "y", so I proceeded with the rest of the "threadirqs" instructions related to grub. That didn't seem to work. > > I altered my /boot/grub2/grub.cfg file to include > > "threadirqs" on the stanza for my kernel, like so, but > > without all the line breaks. > > > > linux /boot/vmlinuz-3.5.5-2.fc17.x86_64 > > root=UUID=77edf07a-a49b-48dd-82c8-2f9e5c8691b7 ro nomodeset > > rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True KEYTABLE=us rd.luks=0 > > LANG=en_US.UTF-8 rhgb quiet threadirqs nouveau.modeset=0 > > rd.driver.blacklist=nouveau > > > > Slightly OT, but wow, that's a whole lot of kernel options ;) I only use > two or three. I left all of that in there from Fedora's installation of the kernel. > Check if your kernel is preemtible (at least, I think that might be a > probable cause) or install a kernel that is preemtible # CONFIG_PREEMPT_RCU is not set CONFIG_PREEMPT_NOTIFIERS=y # CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set > (there's no real-time kernel available for FC17?). CCRMA has kernel-rt-3.4.11-1.rt19.2.fc17.ccrma.x86_64 but it doesn't play nicely with my nVidia card and X config. I changed the X config to use the nouveau driver, which got it to boot to level 5 at least. But the geometry is not good and that driver ignores my 2nd display. I found A LOT of potentially useful information with a websearch for enabling an nVidia driver with a CCRMA kernel. Sorting that out is a possibility. Thanks.... -- Kevin _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
