[Mesa-dev] [PATCH V2] util/disk_cache: compress individual cache entries

[Brian Paul]

On 03/04/2017 07:12 AM, Emil Velikov wrote:
> On 2 March 2017 at 21:52, Timothy Arceri <tarceri at itsqueeze.com> wrote:
>>
>> On 03/03/17 01:49, Emil Velikov wrote:
>>>
>>> Hi Tim,
>>>
>>> On 2 March 2017 at 01:36, Timothy Arceri <tarceri at itsqueeze.com> wrote:
>>>>
>>>> This reduces the cache size for Deus Ex from ~160M to ~30M for
>>>> radeonsi.
>>>>
>>>> I'm also seeing the following improvements in minimum fps in the
>>>> Shadow of Mordor benchmark:
>>>>
>>>> no-cache:                    ~10fps
>>>> with-cache-no-compression:   ~15fps
>>>> with-cache-and-compression:  ~20fps
>>>>
>>>> Note the with cache results are from the second run after closing
>>>> and opening the game to avoid the in-memory cache.
>>>>
>>>> Since we only really care about decompression I went with
>>>> Z_BEST_COMPRESSION as suggested on irc by Steinar H. Gunderson
>>>> who has benchmarked decompression speeds.
>>>>
>>> Attempting to side-step the "which compression is best" topic, I'll
>>> just mention:
>>> zlib has been around for a long time than many others so,
>>> a) chances are smaller that vendors that ship their own, but even if they
>>> do
>>> b) the API should be stable across the system and bundled one.
>>>
>>> If not we can reconsider if things get hairy ;-)
>>>
>>> A couple of small suggestions below.
>>>
>>>
>>>> +ZLIB_REQUIRED=1.2.8
>>>>
>>> Any particular reason behind this version - afaict it's released in
>>> 2013 and I'm wondering if some distros may be slow/missing it.
>>>
>>
>> It's what's shipped with Fedora and therefore what I tested with. If distros
>> are lagging behind I don't think this is a problem we need to be concerned
>> with, it may prompt them to upgrade which I don't think is a bad thing.
>>
> I was thinking about Debian and friends, which tend to be slower than others.
>>From what I can tell they rarely consider external factors as a reason
> to update.
>
> That aside, they have 1.2.7 for "oldstable" and 1.2.8 for everything
> else so everything's fine.

FWIW, RHEL 7.2 (haven't looked at 7.3 yet) only has zlib 1.2.7.  Mesa 
builds fine with 1.2.7 if I override ZLIB_CFLAGS and ZLIB_LIBS, but I 
haven't tested the shader cache.

Can we lower the check to 1.2.7?  Otherwise, I guess I could hack around 
it in our build script.

-Brian