Re: Decreasing time for `rsa_init`

[Paul Menzel]

Dear Stephan, dear Linux folks,


Am 13.07.2017 um 20:20 schrieb Paul Menzel:

> Am Mittwoch, den 12.07.2017, 19:38 +0200 schrieb Paul Menzel:
>
> > On 07/12/17 19:28, Stephan MÃller wrote:
> > > Am Mittwoch, 12. Juli 2017, 12:59:58 CEST schrieb Paul Menzel:
> > > > Building CRYPTO_RSA not as module, but into the Linux kernel,
> > > > `rsa_init()` takes 130 ms on an ASRock E350M1.
> > > >
> > > > (Timings are shown by adding `initcall_debug` to Linux command
> > > > line [1].
> > > > The times are visualized by `analyze_boot.py` from pm-graph [2]
> > > > or `systemd-bootchart`.)
> > > >
> > > > This is quite a lot of time compared to other modules, and I
> > > > wonder if
> > > > there are ways to decrease that time other than building it as a
> > > > module,
> > > > and not signing modules?
> > >
> > > Is the testmgr compiled? If yes, the self test may take that time.
> >
> > It looks like it is, as the tests are not disabled.
> >
> > ```
> > $ grep MANAGER_DISABLE_TESTS .config
> > # CONFIG_CRYPTO_MANAGER_DISABLE_TESTS is not set
> > ```
> >
> > Iâll try an image without the tests, and will report back.
>
> Thank you. That was it. Disabling the tests reduces the time to 51 Îs.
>
> ```
> kernel: calling  rsa_init+0x0/0x40 @ 1
> kernel: initcall rsa_init+0x0/0x40 returned 0 after 51 usecs
> ```
>
> Itâd be nice to be able to disable the testmgr during run-time by
> adding an option to the Linux Kernel command line for example.

To follow up with this, thanks to commit 9e5c9fe4 (crypto: testmgr - Add 
a flag allowing the self-tests to be disabled at runtime.), present 
since Linux 4.7, this can be disabled at run-time by adding 
`cryptomgr.notests` to the Linux command line.

I just donât know, how a user should find this parameter, that means, 
what module(?) this parameter belongs to, and is visible with `modinfo 
<module_name>`.

Additionally in `crypto/algboss.c`, that parameter doesnât seem to apply.

```
   214	static int cryptomgr_test(void *data)
   215	{
   216		struct crypto_test_param *param = data;
   217		u32 type = param->type;
   218		int err = 0;
   219	
   220	#ifdef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
   221		if (disable_tests)
   222			goto skiptest;
   223	#endif
   224	
   225		if (type & CRYPTO_ALG_TESTED)
   226			goto skiptest;
   227	
   228		err = alg_test(param->driver, param->alg, type, CRYPTO_ALG_TESTED);
   229	
   230	skiptest:
   231		crypto_alg_tested(param->driver, err);
   232	
   233		kfree(param);
   234		module_put_and_exit(0);
   235	}
```


Kind regards,

Paul


> > > > [1] http://elinux.org/Initcall_Debug
> > > > [2] https://github.com/01org/pm-graph