lib/raid6: add option to skip algo benchmarking

This is helpful for systems where fast startup time is important.
It is especially nice to avoid benchmarking RAID functions that are
never used (for example, BTRFS selects RAID6_PQ even if the parity RAID
mode is not in use).

This saves 250+ milliseconds of boot time on modern x86 and ARM systems
with a dozen or more available implementations.

The new option is defaulted to 'y' to match the previous behavior of
always benchmarking on init.

Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
Daniel Verkamp 2018-11-12 15:26:52 -08:00 committed by Shaohua Li
parent 0437de4fa0
commit be85f93ae2
3 changed files with 16 additions and 0 deletions

View file

@ -163,6 +163,11 @@ static inline const struct raid6_calls *raid6_choose_gen(
if ((*algo)->valid && !(*algo)->valid())
continue;
if (!IS_ENABLED(CONFIG_RAID6_PQ_BENCHMARK)) {
best = *algo;
break;
}
perf = 0;
preempt_disable();