import Base: getindex, size, setindex!
struct LinearSubArray{T} <: AbstractVector{T}
    v::Vector{T}
    offset::Int
    len::Int
end
getindex(x::LinearSubArray, i) = @inbounds x.v[i + x.offset - 1]
setindex!(x::LinearSubArray, v, k) = @inbounds x.v[k + x.offset - 1] = v
size(x::LinearSubArray) = (x.len, )

lv = LinearSubArray(v2, 500, 1000);

julia> @btime sort!(vv) setup = (vv = deepcopy($v)) evals = 1;
  13.110 μs (0 allocations: 0 bytes)

julia> @btime sort!(vv) setup = (vv = deepcopy($lv)) evals = 1;
  12.037 μs (0 allocations: 0 bytes)

v = rand(100_000);
v2 = rand(200_000);
v2[50_000:149_999] .= v;
vview = @view v2[50_000:149_999];

julia> @btime sort($v);
  5.938 ms (2 allocations: 781.33 KiB)

julia> @btime sort($vview);
  5.951 ms (2 allocations: 781.33 KiB)

lv = LinearSubArray(v2, 50_000, 100_000);

julia> @btime sort($lv);
  5.899 ms (2 allocations: 781.33 KiB)

julia> @btime sort!(vv) setup = (vv = deepcopy($v)) evals = 1;
  5.777 ms (0 allocations: 0 bytes)

julia> @btime sort!(vv) setup = (vv = deepcopy($lv)) evals = 1;
  5.810 ms (0 allocations: 0 bytes)

julia> @btime sort!(vv) setup = (vv1 = deepcopy($v2); vv = @view vv1[500:1499]) evals = 1;
  17.759 μs (0 allocations: 0 bytes)

julia> versioninfo()
Julia Version 1.7.0-DEV.538
Commit 85354cf8ef (2021-02-15 11:47 UTC)
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-11.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 4