Re: [PATCH ] VMSPLIT config options (with default config fixed)

[Jan Engelhardt <jengelh@linux01.gwdg.de>]

>> >
>> > Mmm.. bad idea.  As much as I'd like the default to be 3GB_OPT, that would
>> > be a big impact to userspace, and there's no point in breaking everyone's
>> > machines when advanced users can just reconfig/recompile to get what they want.
>> >
>> What userspace programs do depend on it?
>
>there is a lot of userspace that assumes they can do 2Gb or even close
>to 3Gb of memory allocations. Databases, java, basically anything with
>threads. Sure for most of these its a configuration option to reduce
>this, but that still doesn't mean it's a good idea to change from the
>existing behavior...
> 
Not to mention that these (almost(*)) fail anyway when you have less than 2 
GB of RAM.

(*) when finally writing to overcommitted memory

Yuck. That sounds like they depend on 64G/64bit allocations on 4G/32bit 
machines.


Jan Engelhardt
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