Page 1 of 1
[Solved] Some sysctl values are lost after suspend/resume
Posted: 21. Feb 2012, 18:43
by GJones
Run 'system -w vm.dirty_bytes=5000000'
Suspend the system...
Resume, and vm.dirty_bytes is 0 again.
Put it in sysctl.conf, run 'sysctl -p', suspend and resume... Same thing.
Word is that this is a feature (no, I've no idea how) and will not be fixed. Given that, what is the least kludgy way to make Salix run 'sysctl -p' on resume?
Re: Some sysctl values are lost after suspend/resume
Posted: 21. Feb 2012, 20:06
by aurlaent
You could create a hook in /etc/pm/sleep.d
https://wiki.archlinux.org/index.php/Pm ... _own_hooks
has some detailed info.
Re: Some sysctl values are lost after suspend/resume
Posted: 21. Feb 2012, 20:43
by GJones
Thanks, that's what I was looking for!
Edit: to be fair this is still a kludge, since stuff not in sysctl.conf won't be applied. Even so, it helps.
Re: Some sysctl values are lost after suspend/resume
Posted: 22. Feb 2012, 22:24
by aurlaent
Sure, but how often are you changing things like that on the fly?
(I guess I haven't found the power of these options)
Re: Some sysctl values are lost after suspend/resume
Posted: 23. Feb 2012, 01:10
by GJones
Well, for starters vm.dirty_bytes is rather handy for preventing I/O starvation on desktops, at the expense of disk throughput. It can prevent those scenarios where some program is writing huge batches of stuff to the disk and other programs can't get a word in edgewise.
Re: Some sysctl values are lost after suspend/resume
Posted: 10. Mar 2012, 20:34
by GJones
Okay, something is going wrong here. sysctl -p is running but the changes are being undone.
Code: Select all
/usr/lib/pm-utils/sleep.d/01grub resume suspend: success.
Running hook /etc/pm/sleep.d/00sysctl resume suspend:
vm.dirty_bytes = 5000000
...
# sysctl vm.dirty_bytes
vm.dirty_bytes = 0
00sysctl is properly set +x and looks like this:
Code: Select all
#!/bin/bash
case $1 in
thaw)
sysctl -p
;;
resume)
sysctl -p
;;
*)
;;
esac
What am I doing wrong?
Re: Some sysctl values are lost after suspend/resume
Posted: 16. Mar 2012, 21:22
by GJones
Hate to do this, but... bump?
Re: Some sysctl values are lost after suspend/resume
Posted: 17. Mar 2012, 11:02
by Shador
Probably something else is running afterwards but I wouldn't know what. You could try this:
Code: Select all
grep -i sysctl /etc/pm/ /usr/lib64/pm-utils/ -r
Apparently this information is from a log:
GJones wrote:Code: Select all
/usr/lib/pm-utils/sleep.d/01grub resume suspend: success.
Running hook /etc/pm/sleep.d/00sysctl resume suspend:
vm.dirty_bytes = 5000000
...
# sysctl vm.dirty_bytes
vm.dirty_bytes = 0
You could try to get some information from there what is resetting them. Possibly by increasing the verbosity.
Re: Some sysctl values are lost after suspend/resume
Posted: 18. Mar 2012, 09:37
by GJones
The only invocation of sysctl I found was this:
Code: Select all
# grep -ir sysctl /usr/lib64/pm-utils/
/usr/lib64/pm-utils/sleep.d/99video: sysctl -w kernel.acpi_video_flags=$acpi_flag
Which I'm pretty sure is not responsible.
Re: Some sysctl values are lost after suspend/resume
Posted: 18. Mar 2012, 15:58
by GJones
N/M got it, it's /usr/lib64/pm-utils/power.d/laptop-mode (writing directly to /proc/sys/vm/dirty_ratio and whatnot). Overriding that via an empty /etc/pm/power.d/laptop-mode file works okay.