ac100 team mailing list archive

[Jani Monoses <jani.monoses@xxxxxxxxx>]

Same URL as before (armel build), overwriten with new deb with zcache
and cleancahce enabled.


On Wed, Apr 11, 2012 at 11:01 PM, Marc Dietrich <marvin24@xxxxxx> wrote:
> On Wednesday 11 April 2012 22:43:18 Jani Monoses wrote:
>> > One thing missing (not really missing, but kinda wrong) is CONFIG_ZCACHE=y
>> > instead of "=m" (compressor for clean buffer cache pages). Zcache cannot
>> > really be used as a module and upstream has a patch to disable module
>> > support. You may also activate CONFIG_FRONTSWAP (compresses dirty buffer
>> > cache pages). It works fine here, the effect isn't large though.
>>
>> Ok. IIRC frontswap or zcache was causing regressions at one point last
>> year right? I think that is why
>> I did not look at it anymore. I may be confusing that with other
>> caching support bits though.
>
> I don't remember such problems (maybe because of other trouble), but I merged
> quite a few bug fixes over the time. Plus, I don't see any issues here, but
> well... .
>
> Reading my previous mail again, I need to clarify that ZCACHE is the backend
> for cleancache (the one for clean buffer cache) and frontcache (for dirty buffer
> cache). So cleancache only works if zcache=y, otherwise
> /sys/kernel/debug/cleancache shows only zeros. Same holds for frontswap.
>
> So either we try ZCACHE=y, CLEANCACHE=y, and (optionally) FRONTSWAP=y
> or set all to "N" to be on the safe side.
>
> I prefer to enable all, because we have a low mem machine were every bit is
> precious and to have a bit larger testing base until precise is released - I
> guess in April 2012 - oh no, time passes so fast.
>
> So, I'll leave it up to you to enable the caches or not. Remember that you
> also have to specify "zcache" on the kernel cmdline to use them (which is off
> by default I think).
>
> Marc
>