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re: AMAP_SHARED (was Re: XIP)
> - AMAP_SHARED itself is a fine concept; it's used by shared memory.
> 452 error = uvm_map(&vm->vm_map, &attach_va, size, uobj, 0,
> 453 UVM_MAPFLAG(prot, prot, UVM_INH_SHARE,
> UVM_ADV_RANDOM, flags));
> (Note UVM_INH_SHARE == MAP_INHERIT_SHARE).
> I guess MAP_INHERIT_SHARE was added because adding it was easy
> after shared amap was implemented for shared memory?
MAP_INHERIT_SHARE was originally MAP_INHERIT, and came from
> - For highly tuned, XIP'ed systems, programs should be designed to
> avoid .data, because they're COW'ed to page cache sooner or later.
why is this a problem?
if the data is needed, and it will be written to, then these pages
will be allocated (COW'd) eventually, and the same space will be used.
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