### Description

The sqlops module run into an infinite loop and print continously this line to the stderr (or stdout):

22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22]

### Troubleshooting

#### Reproduction

Set log_stderror=yes Load the sqlops module and configure it with a bad DB host.

Example: ``` log_stderror=yes loadmodule "sqlops.so" modparam("sqlops","sqlcon","main=>postgres://abc:abc@INVALID_HOST/test") ```

#### Debugging Data

#### Log Messages

``` 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] 22(17903) ERROR: <core> [core/io_wait.h:1040]: io_wait_loop_epoll(): epoll_wait(10, 0x2ab72bb7b690, 0, 5000): Invalid argument [22] ... ```

#### SIP Traffic

<!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->

``` (paste your sip traffic here) ```

### Possible Solutions

<!-- If you found a solution or workaround for the issue, describe it. Ideally, provide a pull request with a fix. -->

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` 5.1.6 ```

* **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`) -->

``` Centos 7 Kernel: 3.10.0-514.26.1.el7.x86_64 ```