> Since Sandy Bridge at least, each CPU has its own PCIe interface. Presumably, if you're doing user-space kernel bypass IO you want your workload on the same CPU that your IO devices are connected to.
I think you meant the whole socket here. Yes, this is one of the reasons why many shops move away from 4-socket rigs as it sometimes gets really challenging to partition PCIe/cpu/memory resources when running multiple latency critical processes. On Thu, 25 May 2017, 00:49 Ross Bencina, <[email protected]> wrote: > On 22/05/2017 5:47 PM, Himanshu Sharma wrote: > > Did you find a satisfactory reason for not isolating cpu 0, maybe some > > low level OS code that is bound to run on core 0? > > Throwing this out there for comment: > > In addition to Linux kernel internals, you might want to consider which > CPU your IO is connected to. Since Sandy Bridge at least, each CPU has > its own PCIe interface. Presumably, if you're doing user-space kernel > bypass IO you want your workload on the same CPU that your IO devices > are connected to. Otherwise you want the kernel running on the CPU that > is directly connected to IO. > > Or you could work out the CPU isolation first then connect IO as > appropriate. > > Ross. > > -- > You received this message because you are subscribed to the Google Groups > "mechanical-sympathy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
