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 > _______________________________________________ > sssd-devel mailing list > [email protected] > https://lists.fedorahosted.org/admin/lists/[email protected] _______________________________________________ sssd-devel mailing list [email protected] https://lists.fedorahosted.org/admin/lists/[email protected]
