4 ms·
how do you access this DDIO feature if you are writing a C or C++ application? intrinsics?
by b20000 5y ago
how do you access this DDIO feature if you are writing a C or C++ application? intrinsics?
- medawsonjr 5y agoIt's configurable via MSR. You can also disable it system-wide or on a PCIe port basis. I detailed it all here: https://www.jabperf.com/skip-the-line-with-intel-ddio/ https://www.jabperf.com/skip-the-line-with-intel-ddio/
- tbr1 5y agoDDIO operates mostly transparently to software, with the I/O controller feeding DMAs into a slice of L3. Hardware can opt out by setting PCIe TLP header hints, and you have some system-wide configurability via MSRs, but it's not something a userspace application can take into its own hands.