tree 71c85aec7062402d2b4ed66eb0b035763ccacfc1
parent b8aebc83523691be2b37e87c62099d700b0473c7
author Jan Stancek <jstancek@redhat.com> 1571146236 +0200
committer Jan Stancek <jstancek@redhat.com> 1571382799 +0200

pcrypt_aead01: break early when approaching timeout

PowerNV (P9 witherspoon, 176CPUs) systems running latest upstream
kernel (5.3.6) have been observed to come very close to test timeout
and also sporadically fail, because they couldn't complete 10000
iterations in time.

Each iteration of test leads to modprobe of cryptomgr and crypto
framework running number of tests, taking up to ~70ms per iteration.

Looking at traces, a significant contributor is wakeup time. After
one crypto test is done, it takes ~0.5ms for other tests to resume:
  (gettimeofday_us)
  1571141551769329      7 kworker/1:1(897):<-crypto_req_done
  1571141551769843   1603 cryptomgr_test(3813):

Booting with powersave=off cuts this latency significantly, single
iteration of test completes in ~10ms.

But changing kernel defaults isn't very practical solution, hence patch
is watching for timeout approaching and breaks the loop early.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>