From 77f5bdc240b46a761e7da3c2f0a6ce81d25c6f59 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 11 Mar 2020 15:13:33 +0100 Subject: [PATCH] api-extensions: add "pidfd" api extension Signed-off-by: Christian Brauner --- doc/api-extensions.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/doc/api-extensions.md b/doc/api-extensions.md index 9413c7df9..750696595 100644 --- a/doc/api-extensions.md +++ b/doc/api-extensions.md @@ -124,3 +124,7 @@ a pure unified cgroup layout. # init\_pidfd This adds a new API function `init_pidfd()` which allows to retrieve a pidfd for the container's init process allowing process management interactions such as sending signal to be completely reliable and rac-e free. + +# pidfd + +When running on kernels that support pidfds LXC will rely on them for most operations. This makes interacting with containers not just more reliable it also makes it significantly safer and eliminates various races inherent to PID-based kernel APIs. LXC will require that the running kernel at least support `pidfd_send_signal()`, `CLONE_PIDFD`, `P_PIDFD`, and pidfd polling support. Any kernel starting with `Linux 5.4` should have full support for pidfds. -- 2.47.2