[Mesa-dev] [PATCH 7/7] android: set '/sdcard/' as MESA_GLSL_CACHE_DIR by default

[Jordan Justen]

On 2018-01-19 03:03:43, Tapani Pälli wrote:
> On 01/19/2018 11:22 AM, Jordan Justen wrote:
> > On 2018-01-18 22:08:17, Tapani Pälli wrote:
> >> On 01/18/2018 08:18 PM, Jordan Justen wrote:
> >>> On 2018-01-15 04:31:43, Tapani Pälli wrote:
> >>>> This can/should be modified depending on needs. AFAIK by default,
> >>>> this is the only path that can be read/written to by anyone.
> >>>>
> >>>> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
> >>>> ---
> >>>>    Android.common.mk | 1 +
> >>>>    1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/Android.common.mk b/Android.common.mk
> >>>> index 52dc7bff3b..7edbbfc0f2 100644
> >>>> --- a/Android.common.mk
> >>>> +++ b/Android.common.mk
> >>>> @@ -47,6 +47,7 @@ LOCAL_CFLAGS += \
> >>>>    LOCAL_CFLAGS += \
> >>>>           -DANDROID_API_LEVEL=$(PLATFORM_SDK_VERSION) \
> >>>>           -DENABLE_SHADER_CACHE \
> >>>> +       -DMESA_GLSL_CACHE_DIR="/sdcard" \
> >>>
> >>> Is this used when EGL_ANDROID_blob_cache is being used?
> >>>
> >>> My thought is that if we are running under android with
> >>> EGL_ANDROID_blob_cache, then we should never attempt to write any
> >>> files with src/util/disk_cache.c. This might cause a little rework,
> >>> since the shader cache want to write/manage the index file, but can we
> >>> skip this and only use the blob cache read/write function when
> >>> EGL_ANDROID_blob_cache is available?
> >>
> >> I'm a bit pessimistic about that. Since cache location depends on
> >> running app that would mean every app has it's own index (that not
> >> really a problem though but is different from desktop).
> > 
> > I suspect that the blob_cache is app specific. Therefore it also makes
> > sense that the index would be app specific.
> > 
> >> The big problem I see there that index will be then 'just another
> >> cache entry', I'll have to get more familiar with Android's
> >> implementation to see if there would be way to make this entry
> >> 'special' so that it would not touch it.
> > 
> > My suggestion was that we should scrap the index entirely when in
> > EGL_ANDROID_blob_cache mode. Essentially the Android OS is managing
> > the cache index for us, so hopefully we don't need to maintain one.
> 
> One issue to tackle is that currently _mesa_glsl_compile_shader uses 
> disk_cache_has_key() for detecting if we can skip shader compilation. 
> This uses 'stored_keys' which is mmap of the index file.

It looks like it would be easy to implement 'has_key' with the
blob_cache get function. So, I think we could still keep the same
external interface for disk_cache, but internally it can use
blob_cache when present.

-Jordan