Question on glibc: free() API

[Bizhan Gholikhamseh (bgholikh)]

Hi all,
We are trying to understand a system performance issue with our system.
We are capturing stack calls when a thread in application is suspended
and we see the following stack:

free(...)
Pthreat_mutex_init(...)
pthread_wait_for_restart_signal(...)
pthread_sigsuspend(...)

My question is: the thread which calls free() is suspended, why? And
under what condition it becomes runnable.

Many thanks in advance,
Bizhan