is ccache working effectively?

Maurizio Cimadamore maurizio.cimadamore at
Fri Nov 9 10:09:15 UTC 2018

That does the trick, thanks.

I take a very small hit in the cold cache case, but then I get huge 
boost once the cache is hot.

cache hit (direct)                  1629
cache hit (preprocessed)             115
cache miss                             1
cache hit rate                     99.94 %
cleanups performed                     0
files in cache                      5121
cache size                         317.6 MB
max cache size                       5.0 GB

And, in my laptop the clean/build time went down from 11 mins to 3 :-)


On 09/11/2018 00:24, Erik Joelsson wrote:
> You can try --disable-precompiled-headers and see if that helps. We 
> have had special considerations for combining these features in the 
> past, but it's certainly a source of trouble for ccache.
> /Erik
> On 2018-11-08 16:20, Maurizio Cimadamore wrote:
>> On 08/11/2018 20:31, Erik Joelsson wrote:
>>> I think we need more details here to figure it out, but it doesn't 
>>> surprise me that hotspot is the part that's failing. Building 
>>> hotspot is way more complex than the rest. 
>> Digging more into the command lines of the various HS files, they 
>> include many generated sources and, also this folder:
>> build/<CONF>/hotspot/variant-server/libjvm/objs/precompiled
>> Now, I don't know exactly how ccache deals with PCH but I notices 
>> that every time that the files in this folder are regenerated by the 
>> build (I can easily do that by rerunning the same command line that 
>> is stored inside the , a ccache miss follows.
>> Maurizio

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