clang: set the default pigz thread

pigz, which stands for parallel implementation of gzip, is a
fully functional replacement for gzip that exploits multiple
processors and multiple cores to the hilt when compressing data.

do_package uses pigz to compress data to speed up the time
if there is pigz available on the build server.

But for some big package such as clang, there comes below
error during do_package.
gzip: stdout: Cannot allocate memory
tar: TOPDIR/sstate-cache/20/80/sstate:clang:cortexa57-wrs-linux:10.0.1:r0:cortexa57:3:20808f8a746b00ec9470a81057c8595d878cfe8c565cfbcbbaa3ea870528ee34_package.tgz.QF5dss8M: Wrote only 8192 of 10240 bytes
tar: Child returned status 1
tar: Error is not recoverable: exiting now

So set the default pigz thread for clang and the user also can
customize the pigz thread such as PIGZ_pn-clang = "-p 3" for
clang in local.conf to avoid eating so much memory.

Signed-off-by: Mingli Yu <mingli.yu@windriver.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/recipes-devtools/clang/clang.inc b/recipes-devtools/clang/clang.inc
index a99049d..41ba7bb 100644
--- a/recipes-devtools/clang/clang.inc
+++ b/recipes-devtools/clang/clang.inc
@@ -20,4 +20,7 @@ LLDBMD5SUM = "2e0d44968471fcde980034dbb826bea9"
 
 LLVM_LIBDIR_SUFFIX="${@d.getVar('baselib').replace('lib', '')}"
 
+# set the default pigz thread
+export PIGZ = "-p ${@oe.utils.cpu_count(at_least=2)}"
+
 require common.inc