Re: RFC: Changing default ggc-min-expand on mips and mipsel?

Aurelien Jarno <[email protected]> Tue, 18 Oct 2016 23:03:00 +0200

Newsgroups	gmane.linux.debian.ports.mips
Message-ID	<[email protected]>

On 2016-10-18 15:04, James Cowgill wrote:
> Hi,
> 
> On 18/10/16 13:49, Aurelien Jarno wrote:
> > On mips and mipsel, we have more and more packages failing to build from
> > source with a "virtual memory exhausted" error in GCC, due to the 2GB
> > address space limit. It seems the occurrence is even higher since the
> > switch to GCC 6. The usual answer has been to play with the
> > ggc-min-expand GCC parameter, and many packages do that already [1].
> > 
> > The ggc-min expand parameter defaults to "30% + 70% * (RAM/1GB) with an
> > upper bound of 100% when RAM >= 1GB". In practice all of our build
> > daemons, but also most of the development machines (including the CI20
> > board) are bound to 100%. I therefore wonder if we should change the
> > default at least for mips and mipsel in Debian, and maybe even upstream
> > for 32-bit architectures.
> > 
> > Any opinion or comment about that?
> 
> I think this is a good idea since it is almost "free" and we don't have
> to change lots of packages. I also think changing it on other 32-bit
> arches is a good idea, although they're not as affected as much since
> that have an extra 1GB of virtual memory.

Ok, I'll work on a patch for the debian package then. The next question
is which value should we use? 30% like if the machine had no RAM? 20%
like used by some packages?

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
[email protected]                 http://www.aurel32.net

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