tree 3aae31a915a0c55096dfafb5dbf262f5fcc07b53
parent 5c92dea09585baf385111dad4e4e24e535a2bf0d
author Jonas Larsson <ljonas@google.com> 1570477855 -0700
committer Jonas Larsson <ljonas@google.com> 1570477930 -0700

Allocate cached ION buffers.

We're doing lots of CPU access of ION buffers and with no caching this
access is pretty slow. By allocating with ION_FLAG_CACHED CPU mapped
pages will be cached and for example a memcpy of a decoded 1080p video
frame is about 3x faster. When writing to a buffer from CPU ("software
rendering") ION will ensure proper cache management on munmap.

For cases not involving CPU access (e.g. VPU directly to GPU) this is
a no-op.

In the Android world this corresponds to gralloc-ing with
GRALLOC_USAGE_SW_READ | GRALLOC_USAGE_SW_WRITE.

Change-Id: I52ca0ac7cc4ebfe3cb8a76aa38e437ac9a04cf02