Hello,
we have noticed a possible performance regression related to TCP/TLS in the Kamailio 6.1.x release when installed from packages or from source with cmake, and in Kamailio 6.0 releases only when installed from source with cmake.
There was a change introduced by mistake that disabled certain polling functionality related to the internal TCP stack. It can be observed at startup, or by executing "kamailio -I". See below for further information.
This was fixed today in git master, 6.1 and 6.0 branches. Commit ids are: 54572ce96, f1a333b37b, b906c409.
I believe that it should be only noticeable if you are having a high number of connected devices and/or a high connection rate.
The mentioned fix will be included in the next minor releases of 6.1 and 5.8., as usual.
Best regards,
Henning Westerholt
1. Verification in log files * Affected:
kamailio: INFO: <core> [core/tcp_main.c:5264]: init_tcp(): using poll as the io watch method (auto detected)
* Unaffected:
kamailio: INFO: <core> [core/tcp_main.c:5264]: init_tcp(): using epoll_lt as the io watch method (auto detected)
1. Verification in Kamailio binary: * Affected:
$ kamailio -I | grep "poll methods"
TCP poll methods: poll
* Unaffected: $ kamailio -I | grep "poll methods" TCP poll methods: poll, epoll_lt, epoll_et, sigio_rt, select
-- Kamailio & VoIP services - https://gilawa.comhttps://gilawa.com/
Small correction, it will be included in 6.1 and 6.0 releases, the 5.8 was before the cmake migration.
From: Henning Westerholt via sr-dev sr-dev@lists.kamailio.org Sent: Tuesday, March 24, 2026 1:52 PM To: Kamailio (SER) - Users Mailing List sr-users@lists.kamailio.org; sr-dev@lists.kamailio.org Cc: Henning Westerholt hw@gilawa.com Subject: [sr-dev] possible performance regression in Kamailio 6.1 release related to TCP/TLS
Hello,
we have noticed a possible performance regression related to TCP/TLS in the Kamailio 6.1.x release when installed from packages or from source with cmake, and in Kamailio 6.0 releases only when installed from source with cmake.
There was a change introduced by mistake that disabled certain polling functionality related to the internal TCP stack. It can be observed at startup, or by executing "kamailio -I". See below for further information.
This was fixed today in git master, 6.1 and 6.0 branches. Commit ids are: 54572ce96, f1a333b37b, b906c409.
I believe that it should be only noticeable if you are having a high number of connected devices and/or a high connection rate.
The mentioned fix will be included in the next minor releases of 6.1 and 5.8., as usual.
Best regards,
Henning Westerholt
1. Verification in log files
a. Affected:
kamailio: INFO: <core> [core/tcp_main.c:5264]: init_tcp(): using poll as the io watch method (auto detected)
b. Unaffected:
kamailio: INFO: <core> [core/tcp_main.c:5264]: init_tcp(): using epoll_lt as the io watch method (auto detected)
2. Verification in Kamailio binary:
a. Affected:
$ kamailio -I | grep "poll methods"
TCP poll methods: poll
b. Unaffected: $ kamailio -I | grep "poll methods" TCP poll methods: poll, epoll_lt, epoll_et, sigio_rt, select
-- Kamailio & VoIP services - https://gilawa.comhttps://gilawa.com/
-
Henning Westerholt