[SSSD] Re: [TESTS] FAIL: pam-srv-tests
On Fri, Jun 10, 2016 at 09:26:38AM +0200, Lukas Slebodnik wrote:
ehlo,
I took some time to find out why pam-srv-tests fails so often.
https://fedorahosted.org/sssd/ticket/2994
It is caused by slow execution of function sysdb_cache_password_ex.
(Thu Jun 9 22:13:36:771048 2016) [sssd] [sysdb_cache_password_ex] (0x0100): start.
(Thu Jun 9 22:13:36:771317 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
s3crypt_gen_salt
(Thu Jun 9 22:13:36:771678 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
s3crypt_sha512
(Thu Jun 9 22:13:38:022470 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_new_attrs
(Thu Jun 9 22:13:38:023115 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_attrs_add_string
(Thu Jun 9 22:13:38:023431 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_attrs_add_long
(Thu Jun 9 22:13:38:023829 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_attrs_add_long v2
(Thu Jun 9 22:13:38:024156 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_attrs_add_long v3
(Thu Jun 9 22:13:38:024482 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_attrs_add_uint32
(Thu Jun 9 22:13:38:024816 2016) [sssd] [sysdb_cache_password_ex] (0x0100): Before
sysdb_set_user_attr
(Thu Jun 9 22:13:38:035319 2016) [sssd] [sysdb_cache_password_ex] (0x0100): return eok
As you can see, the execution of function s3crypt_sha512
took almost two seconds.
Is it caused by valgrind all low entropy?
The random data for the salt is already collected in s3crypt_gen_salt().
sha512_crypt_r() basically mingles and password and the salt and does
hash operations.
From a short inspection I can see nothing obvious which might cause such
delay. Maybe nspr_nss_init() if we really have to init NSS at this
point. The main operations in sha512_crypt_r() are heavily CPU bound, so
maybe some scheduler decides that its time for a different process to get
some CPU time?
On the other hand can you give some details why the test fails because
of this delay? It looks a bit like we depend on a specific execution
time either in the test or the main code. If this is the case I think we
would make the code more robust by removing this dependency.
bye,
Sumit
>
> I can try to go deeper and find out which part of function sha512_crypt_r
> is very slow. But it's faster to write to mailing list rather than
> wait for results from CI.
>
> LS
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