Be the first to like this
Most computer architectures provide support for large pages along with the normal base pages. Large pages increase TLB reach allowing applications with a bigger working set to reduce TLB misses and improve performance. However, high costs for copy-on-write faults for large pages cause Redis to face performance penalties while taking
snapshots. Hence, Redis’ documentation recommends turning off Transparent Huge Page support in Linux for low latency operation. We introduce new policies in the Linux kernel for demoting and re-promoting large pages on copy-on-write faults
to improve the latency issues seen when using Redis with Transparent Huge Pages. These policies allow Redis to reap the benefits of using large pages and reduce the latency both during snapshotting and in normal operation.