dirty_writeback_centisecs doesn't change anymore

Barghest · 2008-11-28 12:01:13

Hi,

as recommended everywhere I have vm.dirty_writeback_centisecs=1500 in /etc/sysctl.conf.

This worked for some days but when I checked powertop today it says that the current value is 499.

I then tried echo 1500 > /proc/sys/vm/dirty_writeback_centisecs in /etc/rc.local but no success.

I image there is a coincidence with the installation of acpid. So, could the one influence the other? If yes, what can I do to change the value to 1500?

Thanks

Barghest · 2008-12-01 09:50:10

No one else noticed this?

Barghest · 2008-12-07 10:14:34

Another bump

lucke · 2008-12-07 11:43:38

Check whether that echo line works in the shell.

joephantom · 2008-12-07 21:12:10

lucke wrote:

Check whether that echo line works in the shell.

It does work for me.

I will try it in rc.local.

EDIT: echo 1500 > /proc/sys/vm/dirty_writeback_centisecs in rc.local doesn't work, neither vm.dirty_writeback_centisecs=1500 does in /etc/sysctl.conf

Last edited by joephantom (2008-12-07 21:23:54)

Barghest · 2008-12-08 15:41:13

Same here.

echo 1500 > /proc/sys/vm/dirty_writeback_centisecs as root in console work.

But as joephantom noticed none of the both entries take effect although they're described in the wiki (at least the one in /etc/sysctl.conf)

Last edited by Barghest (2008-12-08 15:41:26)

lucke · 2008-12-08 15:47:30

Works here.

Try using ">>" instead of ">".

Barghest · 2008-12-08 16:07:55

Ok, I'll give it a try but the same occurs with vm.laptop_mode=5 in /etc/sysctl.conf. So I'm a bit confused if there's something going wrong.

What exactly is the difference between > and >>. The other entries in rc.local work with > (e.g. setting cpu governor to ondemand)

Ramses de Norre · 2008-12-08 16:14:15

Do you have conflicting settings in /etc/sysctl.conf ?

Barghest · 2008-12-08 16:26:47

I don't think so

cat /etc/sysctl.conf

#
# Kernel sysctl configuration
#

# Disable packet forwarding
net.ipv4.ip_forward=0

# Disable the magic-sysrq key
kernel.sysrq = 0

# Enable TCP SYN Cookie Protection
net.ipv4.tcp_syncookies = 1

#Strom sparen
vm.dirty_writeback_centisecs = 1500
vm.laptop_mode = 5

/edit: Using >> in /etc/rc.local works for me

Last edited by Barghest (2008-12-08 16:30:40)

ricardofunke · 2010-11-18 09:42:09

I'm facing the same issue.

No clues?

ChoK · 2010-11-18 13:32:58

necro bumping is bad.

You should list what you tried in your post.
Do you use laptop-mode-tools ? When you say same issue what doesn't work?
vm.dirty_writeback_centisec = 1500 in sysctl.conf or echo 1500 > /proc/sys/vm/dirty_writeback_centisecs in rc.local

Does it work after boot ?

lxndr · 2011-07-14 08:03:39

The issue is still existing. Nothing can setup 'dirty_writeback_centisecs' and 'laptop_mode' on start-up. I tried 'sysctl.conf' and 'rc.local'. Neither 'echo > /proc' nor 'echo >> /proc' nor 'sysctl -w' worked. After boot the values are still default. I guess something I am not aware of overrides them.

ChoK · 2011-07-23 07:42:07

if you need to echo something in /proc/sys you need a sleep command before because /etc/rc.local is called before it's populated.
for example I use this :

#!/bin/bash
#
# /etc/rc.local: Local multi-user startup script.

######Disk Advanced Power Management (power management without spindown to prevent disk wear and clicking noises)
hdparm -B 254 /dev/sda

function PM() {
while [[ ! -d /sys || ! -d /proc/sys ]]; do sleep 5;done

######Deactivate nvidia GPU (6W!!!)
echo '\_SB.PCI0.PEG0.GFX0.DOFF' > /proc/acpi/call

######Power Management
echo 1 > /proc/sys/vm/laptop_mode
echo 0 > /proc/sys/kernel/nmi_watchdog
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs
for i in /sys/class/scsi_host/*/link_power_management_policy; do echo min_power > $i; done
echo Y > /sys/module/snd_hda_intel/parameters/power_save_controller
echo 1 > /sys/module/snd_hda_intel/parameters/power_save
for i in /sys/bus/{pci,i2c}/devices/*/power/control; do echo auto > $i; done

######Power Management : already managed
#echo ondemand > /sys/devices/system/cpu/cpu{0,1,2,3}/cpufreq/scaling_governor
#for i in /sys/bus/usb/devices/*/power/autosuspend; do echo 1 > $i; done
#for i in /sys/bus/usb/devices/*/power/level; do echo auto > $i; done
######Power Management : not efficient enough
#echo 1 > /sys/devices/system/cpu/sched_{mc,smt}_power_savings
}
PM &

edit, actually when I log into kde, those value are overridden. Maybe Powerdevil, logging in also triggers remounting my ext4 partition with commit=0, due to pm-utils I think.

Last edited by ChoK (2011-07-23 11:20:17)

Arch Linux

#1 2008-11-28 12:01:13

dirty_writeback_centisecs doesn't change anymore

#2 2008-12-01 09:50:10

Re: dirty_writeback_centisecs doesn't change anymore

#3 2008-12-07 10:14:34

Re: dirty_writeback_centisecs doesn't change anymore

#4 2008-12-07 11:43:38

Re: dirty_writeback_centisecs doesn't change anymore

#5 2008-12-07 21:12:10

Re: dirty_writeback_centisecs doesn't change anymore

#6 2008-12-08 15:41:13

Re: dirty_writeback_centisecs doesn't change anymore

#7 2008-12-08 15:47:30

Re: dirty_writeback_centisecs doesn't change anymore

#8 2008-12-08 16:07:55

Re: dirty_writeback_centisecs doesn't change anymore

#9 2008-12-08 16:14:15

Re: dirty_writeback_centisecs doesn't change anymore

#10 2008-12-08 16:26:47

Re: dirty_writeback_centisecs doesn't change anymore

#11 2010-11-18 09:42:09

Re: dirty_writeback_centisecs doesn't change anymore

#12 2010-11-18 13:32:58

Re: dirty_writeback_centisecs doesn't change anymore

#13 2011-07-14 08:03:39

Re: dirty_writeback_centisecs doesn't change anymore

#14 2011-07-23 07:42:07

Re: dirty_writeback_centisecs doesn't change anymore

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