ccache.bbclass: Set CCACHE_CONFIGPATH to fix race issues
Fixed race issues when parallel build:
ccache: error: /path/to/ccache/i586-poky-linux/mmc-utils/ccache.conf: No such file or directory
ccache: error: /path/to/ccache/i586-poky-linux/mmc-utils/ccache.conf: No such file or directory
This is because we set CCACHE_DIR for earch recipe, and ccache will create a
ccache.conf for each CCACHE_DIR when CCACHE_CONFIGPATH is not set, but there
might be a race issue in parallel build:
ccache gcc file1.c
ccache gcc file2.c
If the two ccache processes use fopen(path, "w") to create ccache.conf at the
same time, the error would happen. Set CCACHE_CONFIGPATH to
meta/conf/ccache.conf can fix the problem, and we can add other configs to the
file when needed.
And also set cache_dir_levels to 1 (default is 2) since each recipe has a cache
dir, thus we don't have too many files in one dir.
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
