partial free/split for ds

[Alexander Tormasov]

sorry, this is not working...

any other ideas how to split single ds without copy of the content?

> 5 нояб. 2020 г., в 12:24, Alexander Tormasov via users <users at lists.genode.org> написал(а):
> 
> Thank you for answering!
> 
>>> Typically, I want to free a part of this ds, e.g., in the middle of it.
>>> Like UUUUUU -> UUUFFU (where Used and Free abbreviation used), keeping mapping and content for all old addresses except freed ones, in the «middle» of area [base_rw, base_rw+SIZE) from above.
>>> 
>> 
>> How about using multiple dataspaces (chunks) in the first place, ie.
>> each U is a separate dataspace and all dataspaces are mapped into a
>> consecutive region in virtual memory?
> 
> I assume that granularity will be too high. 
> e.g. every U could correspond to single 4k page, and this will give a high related metadata structures overhead (need to store it for every page).
> Also, performance will be terrible - imagine that I will try to allocate around 1Gb of ram with "4k pages data spaces» via separate attach_at() and related nested RPC calls…