WPA stream_out form & memory consumption

[Martin Liška]

Previous patch is wrong, I did a mistake in name ;)

Martin

On 03/27/2014 09:52 AM, Martin Liška wrote:
>
> On 03/25/2014 09:50 PM, Jan Hubicka wrote:
>>> Hello,
>>>     I've been compiling Chromium with LTO and I noticed that WPA
>>> stream_out forks and do parallel:
>>> http://gcc.gnu.org/ml/gcc-patches/2013-11/msg02621.html.
>>>
>>> I am unable to fit in 16GB memory: ld uses about 8GB and lto1 about
>>> 6GB. When WPA start to fork, memory consumption increases so that
>>> lto1 is killed. I would appreciate an --param option to disable this
>>> WPA fork. The number of forks is taken from build system (-flto=9)
>>> which is fine for ltrans phase, because LD releases aforementioned
>>> 8GB.
>>>
>>> What do you think about that?
>> I can take a look - our measurements suggested that the WPA memory will
>> be later dominated by ltrans.  Perhaps Chromium does something that 
>> makes
>> WPA to explode that would be interesting to analyze.  I did not managed
>> to get through Chromium LTO build process recently (ninja builds are not
>> my friends), can you send me the instructions?
>>
>> Honza
>>> Thanks,
>>> Martin
>
> There are instructions how can one build chromium with LTO:
> 1) install depot-tools and export PATH variable according to guide: 
> http://www.chromium.org/developers/how-tos/install-depot-tools
> 2) Checkout source code: gclient sync; cd src
> 3) Apply patch (enables system gold linker and disables LTO for a 
> sandbox that uses top-level asm)
> 4) which ld should point to ld.gold
> 5) unsure that ld.bfd points to ld.bfd
> 6) run: build/gyp_chromium -Dwerror=
> 7) ninja -C out/Release chrome -jX
>
> If there are any problems, follow: 
> https://code.google.com/p/chromium/wiki/LinuxBuildInstructions
>
> Martin
>

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