From bf270a5663c67f1ef4edc8656f428d01372df3a5 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Tue, 6 Oct 2020 18:57:43 +0200 Subject: [PATCH] doc/user.rst: document io_uring --- doc/user.rst | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/doc/user.rst b/doc/user.rst index 039b06ea1..00ef9bdeb 100644 --- a/doc/user.rst +++ b/doc/user.rst @@ -1108,6 +1108,19 @@ See :ref:`realtime`. You can safely ignore this, but you won't benefit from real-time scheduling. This only makes a difference if your computer runs programs other than MPD. +Error "Failed to initialize io_uring" +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Linux specific: the io_uring subsystem could not be initialized. This +is not a critical error - MPD will fall back to "classic" blocking +disk I/O. You can safely ignore this error, but you won't benefit +from io_uring's advantages. + +* "Cannot allocate memory" usually means that your memlock limit + (``ulimit -l`` in bash or ``LimitMEMLOCK`` in systemd) is too low. + 64 MB is a reasonable value for this limit. +* Your Linux kernel might be too old and does not support io_uring. + Error "bind to '0.0.0.0:6600' failed (continuing anyway, because binding to '[::]:6600' succeeded)" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~