### Description We are experiencing sticky OOM state after an extended period (several days). `kamcmd` inspection of mem use shows memory consumed (leaked) via `pv_cache_add(347)` calls.

Inspection of that function suggests nothing can ever be dropped from the cache -- rendering it leaky. `_pv_cache_counter` is tested twice but after initialization (to zero) never appears to be assigned (incremented or otherwise) and so the conditions needed to call `pv_cache_drop` are never met.

### Troubleshooting

#### Debugging Data

``` May 5 23:55:40 eng-X X[1107]: 1(105) INFO: qm_sums: count= 1 size= 2048 bytes from core: core/counters.c: cnt_hash_add(383) May 5 23:55:40 eng-X X[1107]: 1(105) INFO: qm_sums: count= 18473 size= 5571880 bytes from core: core/pvapi.c: pv_cache_add(347) May 5 23:55:40 eng-X X[1107]: 1(105) INFO: qm_sums: count= 162 size= 9344 bytes from core: core/pvapi.c: pv_parse_format(1150) ```

### Additional Information

``` kamcmd> ver kamailio 5.2.2 (x86_64/linux) kamcmd> ```

* **Operating System**:

<!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `uname -a`) -->

``` Linux soak 4.15.0-48-generic #51-Ubuntu SMP Wed Apr 3 08:28:49 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux ```