Number of make jobs for bootcycle-images target

[Magnus Ihse Bursie]

What is the intention here? You want build the second part of the boot 
cycle build without setting -j? Is this because we already have a good 
value of -j inherited from an earlier make call?

The fix looks scary, but that's maybe because all of this make-wrapping 
logic is scary.

What if you keep sending JOBS= and then check if JOBS has a value in 
Init.gmk, instead of introducing DISABLE_JOBS?

/Magnus

On 2017-04-04 14:19, Erik Joelsson wrote:
> Hello Alex,
>
> It wasn't a typo, but it was also not correct, as you are pointing 
> out. Setting JOBS to $(JOBS) would disable the jobserver for the sub 
> make process and also risk flooding a smaller system. What we really 
> need is a way to block the setting of -j in the "Init.gmk main" 
> target. Something like this seems to work for me:
>
>
> diff -r 7810f75d016a make/Init.gmk
> --- a/make/Init.gmk
> +++ b/make/Init.gmk
> @@ -303,7 +303,8 @@
>          $(call PrepareSmartJavac)
>          ( cd $(TOPDIR) && \
>              $(NICE) $(MAKE) $(MAKE_ARGS) $(OUTPUT_SYNC_FLAG) \
> -                -j $(JOBS) -f make/Main.gmk $(USER_MAKE_VARS) \
> +                $(if $(DISABLE_JOBS),, -j $(JOBS)) \
> +                -f make/Main.gmk $(USER_MAKE_VARS) \
>                  $(PARALLEL_TARGETS) $(COMPARE_BUILD_MAKE) 
> $(BUILD_LOG_PIPE) || \
>              ( exitcode=$$? && \
>              $(PRINTF) "\nERROR: Build failed for 
> $(TARGET_DESCRIPTION) (exit code $$exitcode) \n" \
> diff -r 7810f75d016a make/Main.gmk
> --- a/make/Main.gmk
> +++ b/make/Main.gmk
> @@ -320,7 +320,7 @@
>          ifneq ($(COMPILE_TYPE), cross)
>        $(call LogWarn, Boot cycle build step 2: Building a new JDK 
> image using previously built image)
>        +$(MAKE) $(MAKE_ARGS) -f $(SRC_ROOT)/make/Init.gmk 
> PARALLEL_TARGETS=$(BOOTCYCLE_TARGET) \
> -          JOBS= SPEC=$(dir $(SPEC))bootcycle-spec.gmk main
> +          DISABLE_JOBS=true SPEC=$(dir $(SPEC))bootcycle-spec.gmk main
>          else
>        $(call LogWarn, Boot cycle build disabled when cross compiling)
>          endif
>
>
> /Erik
>
> On 2017-04-04 13:26, Alex Kashchenko wrote:
>> Hi,
>>
>> Currently in jdk9 bootcycle-images make target is executed with 
>> unlimited number of make jobs. May I ask whether "JOBS=" bit here [1] 
>> is intentional or just a typo and should be "JOBS=$(JOBS)" instead?
>>
>> Current variant works on x86_64 but crashes with native arm32 boot 
>> cycle builds - compilation tasks are spawned faster than being executed.
>>
>>
>> [1] 
>> http://hg.openjdk.java.net/jdk9/jdk9/file/41d9f0545d53/make/Main.gmk#l323
>>
>