if PACKAGE_libopenssl-afalg_sync comment "Build Options" config AFALG_DIGESTS bool "Build support for digest acceleration" help Digests are fast in software, and accessing AF_ALG adds latency, so you'll need a large request (16KB) just to match software speed. This increases memory usage, and has problems when process fork with open digest contexts (openssh will not work because of it). config AFALG_UPDATE_CTR_IV bool "Don't rely on kernel to update CTR IV" default y help Don't count on the kernel driver to update the CTR-mode counter (IV). At least one driver does not update the IV as a workaround for DMA issues. With this option turned on, the engine will keep track of the counter, and the IV will be sent with every update. If fallback is enabled, then the counter needs to be updated by the engine anyway, and sent with the request everytime there's a switch from software to hardware, so this won't bring much gain in that case. config AFALG_ZERO_COPY bool "Use Zero-Copy Mode" help Uses a Zero-Copy interface. Even though it is supposed to improve performance, actual measurements indicate otherwise. endif