svn commit: r326758 - in head/sys/i386: conf include

[Konstantin Belousov]

On Thu, Dec 14, 2017 at 07:59:03PM +0700, Eugene Grosbein wrote:
> On 14.12.2017 19:26, Konstantin Belousov wrote:
> 
> > Sigh. This would make i386 even less usable for everybody, perhaps
> > except you. Because default 3G of UVA is too small for some common tasks
> > (thanks clang, but also e.g. pypy), and you reduce the user address
> > space even more.
> 
> Those who need 3GB of UVA within single process should not use 32 bit system in first place, should they?

Why do you even consider it acceptable to break the configuration just
because you are not interested in the workload ?

3G cumulative VA does not translate into 3G of usable addresses: the bss
is reserved, the address space is fragmented due to need of growing
stack to not conflict with mmaped regions. As result, applications get
slightly less than 2G usable without tricks, and to apply the tricks
apps must know details of the AS layout, i.e. breaking the portability.

386 arch configuration is not perfect but it provides the main intended
service of general-purpose workstation, with some limitation caused by
32bit of address space being somewhat low for modern code. Appliance
flavoring of the default 386 config is unacceptable.  Keep your tweaks
local.