[kernel-xen] Feature Request - zram module

[Gordan Bobic]

 On Wed, 17 Jul 2013 01:01:24 +1000, Steven Haigh <netwiz at crc.id.au> 
 wrote:
> On 17/07/13 00:12, Gordan Bobic wrote:
>> Hi,
>>
>> Would it be OK to enable the zram module in the dom0
>> kernel rpms?
>>
>> I find it extremely handy for things like fast cache
>> tier and swap space for domUs. I'm sure other people
>> might find it useful for this sort of thing, too.
>
> Any chance you can lodge this as an enhancement request via the bug 
> tracker?
>
> http://xen.crc.id.au/bugs

 http://xen.crc.id.au/bugs/view.php?id=14

> I'll do a bit of research and look at including it in 3.10.2-1 if all
> goes well.

 I've built my own kernel for now (I'm still on 3.9.9, Nvidia driver 
 seems
 to have issues with 3.10+xen, but I'll be switching dom0 do an ATI card
 tonight anyway and plan to use it with the open-source driver unless I
 find the 2D performance is really terrible). The preliminary diff is:


 # diff config-3.9.x86_64 config-3.9.x86_64.new
 3c3
 < # Linux/x86 3.9.2 Kernel Configuration
 ---
> # Linux/x86 3.9.9-2.el6xen.x86_64 Kernel Configuration
 92d91
 < CONFIG_ALWAYS_USE_PERSISTENT_CLOCK=y
 3939a3939,3941
> CONFIG_RTC_HCTOSYS=y
> CONFIG_RTC_SYSTOHC=y
> CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
 4171c4173,4175
 < # CONFIG_ZSMALLOC is not set
 ---
> CONFIG_ZRAM=m
> # CONFIG_ZRAM_DEBUG is not set
> CONFIG_ZSMALLOC=y
 4204c4208
 < # CONFIG_ZCACHE is not set
 ---
> CONFIG_ZCACHE=y
 4915c4919
 < CONFIG_CRYPTO_LZO=m
 ---
> CONFIG_CRYPTO_LZO=y

 Will test this tonight. My main use case is ZFS with zvols for backing 
 domU disks, and zram is handly as a L2ARC.