Re: [PATCH 1/2] kbuild: Support split debug info v3

[Dirk Gouders <dirk@gouders.net>]

Andi Kleen <andi@firstfloor.org> writes:

>> echo time make -j4 -s KCFLAGS=-gsplit-dwarf
>> time make -j4 -s KCFLAGS=-gsplit-dwarf
>> echo time make -j4 -s KCFLAGS=-g
>> time make -j4 -s KCFLAGS=-g
>> echo time make -j4 -s KCFLAGS=-gsplit-dwarf
>> time make -j4 -s KCFLAGS=-gsplit-dwarf
>> echo time make -j4 -s KCFLAGS=-g
>> time make -j4 -s KCFLAGS=-g
>> echo time make -j4 -s KCFLAGS=-gsplit-dwarf
>> time make -j4 -s KCFLAGS=-gsplit-dwarf
>> echo time make -j4 -s KCFLAGS=-g
>> time make -j4 -s KCFLAGS=-g
>> 
>> The figures are from last run - but the other runs had compareable times.
>> So in short I see a ~3 seconds speedup - out of 210 seconds.
>> Thats less than I anticipated.
>
> Thanks. How much smaller is it? 
>
> Just saving disk space is a good thing.

Hi Andi,

I applied v3 to rc6+ and did the rudimentary tests that I did with
v1, i.e. make menuconfig, make, make clean, git status and have nothing
to report.

For times an sizes I did tests with my system's .config -- prior to each
`make' I did a `make clean':

split-debug:

# time make -j5 
...

real    6m21.819s
user    22m48.828s
sys     1m1.804s

# du -sh .
2.6G    .

no split-debug:

# time make -j5 
...

real    6m40.311s
user    23m0.648s
sys     1m4.592s

# du -sh .
4.3G    .

Dirk