package_rpm: use zstd instead of xz

zstd has similar time and space performance in compression but is
vastly faster in decompression, which benefits rootfs creation
(especially when installing very large packages) and on-target
package installation.

Also, ensure ZSTD_THREADS doesn't change sstate checksums. The
detailed explanation is in the commit making similar change for
XZ_THREADS.

(From OE-Core rev: e72c0b94554a9bc293844ec2bddb0c04ea19791d)

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index f3ff5b776b..030d29b097 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -816,6 +816,10 @@ XZ_THREADS[vardepvalue] = "1"
 XZ_DEFAULTS ?= "--memlimit=${XZ_MEMLIMIT} --threads=${XZ_THREADS}"
 XZ_DEFAULTS[vardepsexclude] += "XZ_MEMLIMIT XZ_THREADS"
 
+# Default parallelism for zstd
+ZSTD_THREADS ?= "${@oe.utils.cpu_count(at_least=2)}"
+ZSTD_THREADS[vardepvalue] = "1"
+
 # Limit the number of threads that OpenMP libraries will use. Otherwise they
 # may fallback to using all CPUs
 export OMP_NUM_THREADS = "${BB_NUMBER_THREADS}"