[$] The impact of page-table isolation on I/O performance

Ever since kernel page-table isolation(PTI) was introduced as a mitigation for the Meltdown CPU vulnerability, users have worried about how it affects theperformance of their systems. Most of that concern has been directedtoward its impact on computing performance, but I/O performance alsomatters. At the 2018 Linux Storage, Filesystem, and Memory-ManagementSummit, Ming Lei presented some preliminary work he has done to try toquantify how severely PTI affects block I/O operations.