Red Hat Aiming To Address IBRS Mitigation Still Being Too Costly On Performance

Red Hat engineers are working to deal with Indirect Branch Restricted Speculation (IBRS) being too costly for mitigating Spectre V2 and Retbleed on older Intel Xeon Scalable processors. A new patch has been floated to disable IBRS when idle and is working out well at least for Red Hat Enterprise Linux 9 while isn't clear yet if it will be accepted into the upstream kernel...