On 01/05/2015 21:55, John Snow wrote: > Where it makes sense, use the new faster primitives. > For generally small reads/writes such as for the PRDT > and FIS packets, stick with the more wasteful but > easier to debug memread/memwrite. > > For ahci-test; > With this patch: > real 0m4.802s > user 0m3.506s > sys 0m2.393s > > Without this series: > real 0m14.171s > user 0m12.072s > sys 0m12.527s
The overhead of memread is 2, the overhead of base64 is 1.33, also base64 should have a larger cost of computing each byte. It doesn't add up. Could it be simply that calling qtest_send (and hence vsnprintf+qemu_chr_fe_write_all, neither of which are speed demons) once per byte is hideously inefficient? :) Paolo
