(ITS#5364) Thread pool efficiency

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B Furuseth
Version: HEAD
OS: 
URL: http://www.openldap.org/lists/openldap-devel/200802/msg00003.html
Submission from: (NULL) (129.240.203.232)
Submitted by: hallvard


ITS filed for the changes in thread "Thread pool efficiency",
openldap-devel, Feb 2008.

slapd spends too much time contending for ltp_mutex in
the thread pool (libldap_r/tpool.c).

Applying some easy fixes first: Move work out of the region
where pool_submit() and pool_wrapper hold the mutex locked.
Also slapd/result.c checks if the pool is paused every 64
entries and if so returns LDAP_BUSY, it needs no lock for that.