Applying CPU Limits - Revision history

Glenn: +cat

2011-10-21T19:08:23Z

+cat

Bobnormal: /* Kernel config */ zcat > gzip -d

2010-02-16T09:40:03Z

‎Kernel config: zcat > gzip -d

217.128.26.129: /* Applying CPU limits */

2009-12-03T14:17:48Z

‎Applying CPU limits

76.31.144.66: /* Kernel config */

2009-03-27T01:33:12Z

‎Kernel config

SilvioRhatto: Initial version

2008-12-27T01:02:39Z

Initial version

New page

= Applying CPU limits =

This is a short summary on how to apply limits. This doesn't cover how to choose the values but just on how to apply the numbers in a running vserver without saving the configuration.

== Kernel config ==

First check whether the kernel is with '''CONFIG_VSERVER_HARDCPU''' enabled:

# cat /boot/config-blah | grep CONFIG_VSERVER_HARDCPU
CONFIG_VSERVER_HARDCPU=y

== Context flag ==

Then check if the vserver you want to apply limits has the [http://linux-vserver.org/Capabilities_and_Flags#Context_flags_.28cflags.29 sched_hard] context flag enabled by checking the contents of ''/proc/virtual/<xid>/status''. The sched_hard flag is ''0x00000100'', so you have to find this value summed up in the vserver flag (see [http://www.mail-archive.com/vserver@list.linux-vserver.org/msg10448.html this message] for details). If its not enabled, use the following command (more info [http://www.mail-archive.com/vserver@list.linux-vserver.org/msg08385.html here]):

vattribute --set --xid <xid> --flag sched_hard

== Setting the limits ==

Then you should be able to set the limits with a command like this one (more info [http://oldwiki.linux-vserver.org/vsched+explained here]):

vsched --xid <xid> --fill-rate <fill-rate> --interval <interval> \
--fill-rate2 <fill-rate2> --interval2 <interval2> \
--tokens-max <tokens-max> --tokens-min <tokens-min> --idle-time --force

it's important to use the option ''--force'' so the limit is applied at the same time in the cpus. If you want to enable fair share (i.e, idle-time) for the vserver, make sure to use the ''--idle-time'' option at the previous command.

Then you should check at ''/proc/virtual/<xid>/sched'' (more info [http://linux-vserver.org/ProcFS#sched here]). Try a command like

watch -n1 cat /proc/virtual/<xid>/sched

If the collum "Ticks spent on hold" is greater than zero and the flag "On hold (H) or running (R)" assumes the hold value, then its working :)

If you want to remove the scheduling, use the command

vattribute --set --xid <xid> --flag ~sched_hard

But remember that these instructions just cover setting limits in a running vserver. To save the values you choose please refer to the [http://www.nongnu.org/util-vserver/doc/conf/configuration.html great flower page].

← Older revision		Revision as of 19:08, 21 October 2011
Line 40:		Line 40:

	But remember that these instructions just cover setting limits in a running vserver. To save the values you choose please refer to the [http://www.nongnu.org/util-vserver/doc/conf/configuration.html great flower page].		But remember that these instructions just cover setting limits in a running vserver. To save the values you choose please refer to the [http://www.nongnu.org/util-vserver/doc/conf/configuration.html great flower page].
		+
		+	[[Category:Documentation]]

@@ Line 11: / Line 11: @@
     CONFIG_VSERVER_HARDCPU=y
-Note: With newer kernels, the config of the currently running kernel can be found with `cat /proc/config.gz | gzip -d`.
+Note: With newer kernels, the config of the currently running kernel can be found with `zcat /proc/config.gz | grep VSERVER`.
 == Context flag ==

← Older revision		Revision as of 14:17, 3 December 2009
Line 2:		Line 2:

	This is a short summary on how to apply limits. This doesn't cover how to choose the values but just on how to apply the numbers in a running vserver without saving the configuration.		This is a short summary on how to apply limits. This doesn't cover how to choose the values but just on how to apply the numbers in a running vserver without saving the configuration.
		+	note: you can find soft/hard cpu limit with cgroups for vserver2.3 on [[util-vserver:Cgroups]]

	== Kernel config ==		== Kernel config ==