On 12/09/2013 7:59pm, Giampaolo Rodola' wrote:Do you have a reference? Wikipedia may not be reliable, but it seems to think otherwise:
Given that multiple processes cannot take any advantage of hyper
threading technology then maybe it makes sense for multiprocessing to
expose a physical_cpu_count() function in order to preemptively figure
out how many processes to spawn.
Hyper-threading works by duplicating certain sections of the processor—
those that store the architectural state— but not duplicating the main
execution resources. This allows a hyper-threading processor to appear
as the usual "physical" processor and an extra "logical" processor to
the host operating system (HTT-unaware operating systems see two
"physical" processors), allowing the operating system to schedule two
threads or processes simultaneously and appropriately.
^^^^^^^^^