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

[Eugene Grosbein]

On 14.12.2017 22:23, 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 ?

I do not consider it is acceptable. I'm trying to find compromise.

> 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.

Do you think that kstack overflow of general-purpose workstation using NFS
or IPv6 or WiFi with SCTP is OK? I do not.