Am Montag, 9. November 2020, 20:31:02 CET schrieb Paul Menzel: Hi Paul, > Dear Linux folks, > > > By mistake I built `XFRM_ESP` into the Linux kernel, resulting in > > CONFIG_CRYPTO_SEQIV=y > CONFIG_CRYPTO_ECHAINIV=y > > and also the Jitterentropy RNG to be built in. > > CRYPTO_JITTERENTROPY=y > > So, on the Asus F2A85-M PRO starting Linux 4.10-rc3 with > `initcall_debug`, the init method is run unconditionally, and it takes > 17.5 ms, which is over ten percent of the overall 900 ms the Linux Hm, 17.5 / 900 = 2%, or am I missing something? > kernel needs until loading the init process. > > [ 0.300544] calling jent_mod_init+0x0/0x2c @ 1 > [ 0.318438] initcall jent_mod_init+0x0/0x2c returned 0 after > 17471 usecs > > Looking at the output of systemd-bootchart, it looks like, that this > indeed delayed the boot a little, as the other init methods seem to be > ordered after it. > > I am now building it as a module, but am wondering if the time can be > reduced to below ten milliseconds. What you see is the test whether the Jitter RNG has a proper noise source. The function jent_entropy_init() is the cause of the operation. It performs 1024 times a test to validate the appropriateness of the noise source. You can adjust that with the TESTLOOPCOUNT in this function. But I am not sure adjusting is a wise course of action. Ciao Stephan
