[Bug 44375] Some 32-bit games crash when they exhaust their VM addressing space (Path of Exile, Dragon Age: Origins, NecroVisioN)

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=44375

--- Comment #21 from Konstantin  ---
I see that even plain `wine notepad` has VSS of 2.6G. That makes me doubt it
has anything to do with drivers, this gotta be something in Wine internals.

I spend some hours today trying to figure out where such amount of VSS was
allocated by tracing `mmap` and `mumap` calls, but haven't succeeded at that
(there's simply too many of them, so I tried lots of various heuristics to pin
down where exactly that memory came from, but to no avail).

Still, there is something interesting: when doing a `cat /proc/$(pgrep
notepad)/smaps | less`, there's this memory region with size of 1.9G:

80000000-f7aa0000 ---p 00000000 00:00 0
    Size:            1960576 kB
    KernelPageSize:        4 kB
    MMUPageSize:           4 kB
    Rss:                   0 kB
    Pss:                   0 kB
    Shared_Clean:          0 kB
    Shared_Dirty:          0 kB
    Private_Clean:         0 kB
    Private_Dirty:         0 kB
    Referenced:            0 kB
    Anonymous:             0 kB
    LazyFree:              0 kB
    AnonHugePages:         0 kB
    ShmemPmdMapped:        0 kB
    FilePmdMapped:         0 kB
    Shared_Hugetlb:        0 kB
    Private_Hugetlb:       0 kB
    Swap:                  0 kB
    SwapPss:               0 kB
    Locked:                0 kB
    THPeligible:    0
    VmFlags: mr mw me nr sd

*Clean and *Dirty pages are all zeroes, as if the region is completely unused.
Ha!