Regression is due to decompression overhead. From build 7.1.0-1887 onwards, plasma will compress on swapin. If scans accesses only compressed pages, they will be slower due to decompression overhead. This can occur even when there is sufficient memory between usage and quota. To overcome this, compression on swapin can be performed only when there is memory pressure and with this patch, the performance for this test is back to normal. But, this can be bad for cases where the hot set does not change or gets swapped-out/swapped-in and the hot set does not fit in quota as in the case of the new compression tests. In these tests, regression is observed due to lower resident ratio from not compressing.