Why is left (symmetric) so widely used? even some low level

>>59172669
Most IO devices generate MSI-X interrupts, which any arbitrary available core can handle, as well as being able to do DMA (and thus avoiding relying on a CPU all together in order to transfer data to buffers in memory). It makes much more sense to try to avoid shuffling data across CPU cores (due to caches 'n' stuff).

>>59172669
I think it's because most operating systems come from a time there were no multiple cores.

>>59172669

Because the "operating system" isn't one single thing retard. It's a bunch of stuff, like GNU + Linux.

>>59172722

oh,

>Finally, MSI-X, an extension to the MSI model, which is introduced in PCI 3 .0, adds support
for 32-bit messages (instead of 16-bit), a maximum of 2048 different messages (instead of just
32), and more importantly, the ability to use a different address (which can be dynamically de-
termined) for each of the MSI payloads . Using a different address allows the MSI payload to be
written to a different physical address range that belongs to a different processor, or a different
set of target processors, effectively enabling nonuniform memory access (NUMA)-aware inter-
rupt delivery by sending the interrupt to the processor that initiated the related device request .
This improves latency and scalability by monitoring both load and closest NUMA node during
interrupt completion


well I guess that makes sense somewhat.