On Fri, Jun 10, 2016 at 04:42:51PM +0200, Lukas Slebodnik wrote: > On (10/06/16 12:07), Sumit Bose wrote: > >On Fri, Jun 10, 2016 at 11:09:49AM +0200, Lukas Slebodnik wrote: > >> On (10/06/16 09:54), Sumit Bose wrote: > >> >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. > >> > > >> > >> There are two possitive tests for pam authentication. > >> test_pam_cached_auth_success and > >> test_pam_cached_auth_success_combined_pw_with_cached_2fa > >> > >> The test case is: > >> * simulate authenticate in pam responder -> common_test_pam_cached_auth > >> * back-end should be contacted > >> * store cached password (here is slow function sysdb_cache_password_ex) > >> // we need to explicitely cache password because it is usually done in > >> // back-end > >> * simulate authenticate in pam responder -> common_test_pam_cached_auth > >> * back-end should *NOT* be contacted > >> > >> However, the value of cached_auth_timeout is set to 2 seconds in tests. > >> and therefore back-end is sometimes contected in second authentication. > >> > >> I tried to increase value of cached_auth_timeout 2 -> 4. > >> It helped a little bit but after this change > >> I can still see failures in pam-srv-tests but in differetn tests :-) > >> > >> [ FAILED ] test_pam_preauth_cert_nomatch > >> [ FAILED ] test_pam_preauth_cert_match > >> [ FAILED ] test_pam_preauth_cert_match_wrong_user > >> [ FAILED ] test_pam_preauth_cert_no_logon_name > >> > >> and it does not make sense to me > >> because it failes due to slow p11_child (30 seconds shoudl be enough > >> for p11_child) > > > >yes, 30s should be enough. Even in the cases where p11_child returns > >without a timeout it needs at least 10s to run trough an area of code > >where among other things NSS is initialized. Does the error only happen > >on RHEL6 or on other CI platforms as well? > > > hmm, I cannot reproduce anymore. > > Attached is a patch which increases a cached_auth_timeout. > As Sumit already wrote: sha512_crypt_r() are heavily CPU bound > So it might happen that it will slow with valgrind. > > I used just essential test-suit because I was > interested only in valgrind test which caused problems. > http://sssd-ci.duckdns.org/logs-test/job/0/88/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/89/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/90/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/91/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/92/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/93/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/94/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/95/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/96/summary.html > http://sssd-ci.duckdns.org/logs-test/job/0/97/summary.html > > LS
> From 7db9205d20244e810e4b497a7604696d956f790f Mon Sep 17 00:00:00 2001 > From: Lukas Slebodnik <lsleb...@redhat.com> > Date: Fri, 10 Jun 2016 09:28:37 +0200 > Subject: [PATCH] pam-srv-tests: Increase cached_auth_timeout > > The execution sysdb_cache_password_ex can be slow > due to function s3crypt_sha512 and valgrind slowdown. > > Therefore 2 seconds timeout can be reached > in possitive tests test_pam_cached_auth_success > and test_pam_cached_auth_success_combined_pw_with_cached_2fa > > Resolves: > https://fedorahosted.org/sssd/ticket/2994 > --- > src/tests/cmocka/test_pam_srv.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) If this patch helped in your testing, then I say we should push it.. _______________________________________________ sssd-devel mailing list sssd-devel@lists.fedorahosted.org https://lists.fedorahosted.org/admin/lists/sssd-devel@lists.fedorahosted.org
