Number of make jobs for bootcycle-images target

[Erik Joelsson]

Hello,


On 2017-04-04 14:59, Magnus Ihse Bursie wrote:
> 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?
>
We only want to set the -j flag once since resetting it in a sub make 
call causes us to loose the job server. If there was some other way of 
detecting that we are in a wrapped call, that would certainly help.
> 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?
>
I considered that, but then we lose the currently valid empty value for 
JOBS, which today translates to -j without argument. One could argue 
that it's rarely a good idea to let make just go crazy with processes 
though and in that case we can choose to interpret JOBS="" as don't set 
-j at all.

/Erik

> /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
>>>
>>
>