[LLVMdev] Problems with make

[Csaba Raduly]

Hi all,

On Thu, Jun 12, 2014 at 2:37 PM, Armin Steinhoff  wrote:
> Dan Liew wrote:
>
> If you want things to go faster
>
> * Use the -jN flag with make to build in parallel where N is the maximum
> number of jobs run in parallel. E.g.
>
> $ make -j4
>
>
> This could be critical if you have 4 or less GigaBytes of memory. If you run
> "make -j2" it makes sure that no swapping happens  ... mostly :)
>

I use the following hack to ensure that at most one linker process runs:

~/workspace/LLVM/llvm $ svn diff Makefile.rules
Index: Makefile.rules
===================================================================
--- Makefile.rules    (revision 212018)
+++ Makefile.rules    (working copy)
@@ -767,7 +767,7 @@
 Preprocess.CXX= $(Compile.Wrapper) \
               $(CXX) $(CPP.Flags) $(TargetCommonOpts) $(CPPFLAGS) \
                 $(CompileCommonOpts) $(CXX.Flags) -E
-Link          = $(Compile.Wrapper) \
+Link          = $(Compile.Wrapper) ${FLOCK_COMMAND} \
               $(CXX) $(CXXFLAGS) $(LD.Flags) $(LDFLAGS) \
                 $(TargetCommonOpts) $(Strip)

and the following command line:

$ make -j 8 FLOCK_COMMAND='flock /tmp/linker.lock'

This is more or less required on my 8-processor/8GB RAM machine when
building the debug version :(

-- 
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