[OE-core] [PATCH] populate_sdk_base: use xz -T instead of pixz

[Burton, Ross]

On 9 April 2018 at 21:13, Andre McCurdy <armccurdy at gmail.com> wrote:
> On Mon, Apr 9, 2018 at 8:19 AM, Ross Burton <ross.burton at intel.com> wrote:
>> xz has native support for threaded compression now and SDK creation was the only
>> part of oe-core which is using pixz instead of xz.
>>
>> Not only does this remove pixz-native from the SDK dependencies, but in my
>> limited testing xz -T0 is slightly faster and produces smaller archives than
>> pixz for the same input.
>>
>> Signed-off-by: Ross Burton <ross.burton at intel.com>
>> ---
>>
>>  # We want the MULTIARCH_TARGET_SYS to point to the TUNE_PKGARCH, not PACKAGE_ARCH as it
>> @@ -225,7 +225,7 @@ fakeroot tar_sdk() {
>>         # Package it up
>>         mkdir -p ${SDKDEPLOYDIR}
>>         cd ${SDK_OUTPUT}/${SDKPATH}
>> -       tar ${SDKTAROPTS} -cf - . | pixz > ${SDKDEPLOYDIR}/${TOOLCHAIN_OUTPUTNAME}.tar.xz
>> +       tar ${SDKTAROPTS} -cf - . | xz -T 0 > ${SDKDEPLOYDIR}/${TOOLCHAIN_OUTPUTNAME}.tar.xz
>
> Since -T 0 will use all available CPUs (ie any attempts the user may
> have made to limit parallelism via BB_NUMBER_THREADS or PARALLEL_MAKE
> will be ignored), perhaps it's worth adding something like
> "--memlimit=70%" to try to give some protection for environments with
> lots of CPUs but not so much DRAM?

There's a few places where -T0 is passed already: tar.xz image
creation and opkg creation, so I guess we need to centralise this
somewhere too.

Ross