[pve-devel] Tickless kernel or not

[Thomas Lamprecht]

On 08/05/2015 04:48 PM, Dietmar Maurer wrote:
>>> Redhat uses since RHEL7 a fully tickless kernel. Options:
>>> CONFIG_NO_HZ=y
>>> CONFIG_NO_HZ_FULL=y
>>> CONFIG_RCU_FAST_NO_HZ=n
>>> CONFIG_HZ_1000=y
>>> CONFIG_HZ=1000
>>>
>>> PVE now uses:
>>> CONFIG_NO_HZ=y
>>> CONFIG_NO_HZ_IDLE=y
>>> CONFIG_RCU_FAST_NO_HZ=y
>>> CONFIG_HZ_250=y
>>> CONFIG_HZ=250
>> I just use the default config provided by RH/Ubuntu for that.
>>
>> Does it matter somehow?
> Reading the docs:
>
> https://www.kernel.org/doc/Documentation/timers/NO_HZ.txt
>
> seems the current options are preferred?
Yes, it seem so. It would be more relevant for mobile device (power 
consumption) or with light workload. Both doesn't apply to PVE, so not 
really suitable.