On Fri, Nov 22, 2013 at 3:13 AM, Volker Armin Hemmann
<volkerar...@googlemail.com> wrote:
> Am 21.11.2013 20:52, schrieb Mark Knecht:
>> Hi,
>> I've been having a problem with new versions of Virtualbox hanging
>> my system completely, but only if I use the CONFIG_PREEMPT option.
>> I.e. - Preemptable Kernel (Low Latency Desktop) The problem does not
>> occur if I select Voluntary Preemption.
>>
>> The Oracle guys who do Virtualbox development has asked me to try
>> full preempt but disable the PREEMPT_RCU option as a test. I think
>> possibly Paul McKenney works on the RCU stuff and also frequenct this
>> list so possibly he or someone else here can tell me where I find the
>> option to completely disable the RCU stuff. (If it exists...)
>>
>> I'm currently running gentoo-sources-3.10.19, trying to build 3.10.20.
>>
>> Specifically, here's where I am now:
>>
>> c2RAID6 linux # cat .config | grep PREEMPT
>> CONFIG_TREE_PREEMPT_RCU=y
>> CONFIG_PREEMPT_RCU=y
>> CONFIG_PREEMPT_NOTIFIERS=y
>> # CONFIG_PREEMPT_NONE is not set
>> # CONFIG_PREEMPT_VOLUNTARY is not set
>> CONFIG_PREEMPT=y
>> CONFIG_PREEMPT_COUNT=y
>> CONFIG_DEBUG_PREEMPT=y
>> c2RAID6 linux #
>>
>> I found General Setup-> RCU Subsystem but I'm ot clear what option
>> might allow me to do what I think the Oracle devs are asking me to do.
>>
>> If I need a newer/different kernel let me know.
>>
>> Thanks,
>> Mark
>>
>>
> make menuconfig
> hit slash
> type in RCU
>
> it will tell you where to find stuff
>
>
And the only thing that I see that looks like a candidate says
Symbol: PREEMPT_RCU [=y]
│
│ Type : boolean
│
│ Defined at init/Kconfig:472
which doesn't give me any option to change it in make menuconfig.
If you feel a different option is in there that I'm not seeing I'd
certainly appreciate knowing which one it is.
Under General Setup -> RCU Subsystem using a ? on each line suggests
none of the lines in that section are associated with PREEMPT_RCU. As
you seem to know where it is please let me know.
Thanks,
Mark
