Is a high amount of "I/O wait" expected when running Jay in a QEMU/KVM VM? #815
Description
I downloaded the PKGBUILD + jay.install files locally onto an Arch Linux VM and ran makepkg -si to build Jay.
Using the following Jay config:
# The keymap that is used for shortcuts and also sent to clients.
keymap = """
xkb_keymap {
xkb_keycodes { include "evdev+aliases(qwerty)" };
xkb_types { include "complete" };
xkb_compat { include "complete" };
xkb_symbols { include "pc+us+inet(evdev)" };
};
"""
# Shortcuts that are processed by the compositor.
# The left hand side should be a key, possibly prefixed with modifiers.
# The right hand side should be an action.
[shortcuts]
# The focus-X actions move the keyboard focus to next window on the X.
alt-h = "focus-left"
alt-j = "focus-down"
alt-k = "focus-up"
alt-l = "focus-right"
# The move-X actions move window that has the keyboard focus to the X.
alt-shift-h = "move-left"
alt-shift-j = "move-down"
alt-shift-k = "move-up"
alt-shift-l = "move-right"
# The split-X action places the currently focused window in a container
# and sets the split direction of the container to X.
alt-d = "split-horizontal"
alt-v = "split-vertical"
# The toggle-split action changes the split direction of the current
# container.
alt-t = "toggle-split"
# The toggle-mono action changes whether the current container shows
# a single window or all windows next to each other.
alt-m = "toggle-mono"
# The toggle-fullscreen action toggles the current window between
# windowed and fullscreen.
alt-u = "toggle-fullscreen"
# The focus-parent action moves the keyboard focus to the parent of
# the currently focused window.
alt-f = "focus-parent"
# The open-control-center action opens the control center.
alt-c = "open-control-center"
# The close action requests the currently focused window to close.
alt-shift-c = "close"
# The toggle-floating action changes the currently focused window between
# floating and tiled.
alt-shift-f = "toggle-floating"
# All actions above are so-called simple actions that are identified by
# a string. More complex actions take parameters and are written as a table.
# For example, the exec action spawns an application and has the exec field
# that describes how to spawn the application.
Super_L = { type = "exec", exec = "foot" }
alt-p = { type = "exec", exec = "fuzzel" }
# The quit action terminates the compositor.
alt-q = "quit"
# The reload-config-toml action reloads the TOML configuration file.
alt-shift-r = "reload-config-toml"
# The switch-to-vt action switches to a different virtual terminal.
ctrl-alt-F1 = { type = "switch-to-vt", num = 1 }
ctrl-alt-F2 = { type = "switch-to-vt", num = 2 }
ctrl-alt-F3 = { type = "switch-to-vt", num = 3 }
ctrl-alt-F4 = { type = "switch-to-vt", num = 4 }
ctrl-alt-F5 = { type = "switch-to-vt", num = 5 }
ctrl-alt-F6 = { type = "switch-to-vt", num = 6 }
ctrl-alt-F7 = { type = "switch-to-vt", num = 7 }
ctrl-alt-F8 = { type = "switch-to-vt", num = 8 }
ctrl-alt-F9 = { type = "switch-to-vt", num = 9 }
ctrl-alt-F10 = { type = "switch-to-vt", num = 10 }
ctrl-alt-F11 = { type = "switch-to-vt", num = 11 }
ctrl-alt-F12 = { type = "switch-to-vt", num = 12 }
# The show-workspace action switches to a workspace. If the workspace is not
# currently being used, it is created on the output that contains the pointer.
alt-F1 = { type = "show-workspace", name = "1" }
alt-F2 = { type = "show-workspace", name = "2" }
alt-F3 = { type = "show-workspace", name = "3" }
alt-F4 = { type = "show-workspace", name = "4" }
alt-F5 = { type = "show-workspace", name = "5" }
alt-F6 = { type = "show-workspace", name = "6" }
alt-F7 = { type = "show-workspace", name = "7" }
alt-F8 = { type = "show-workspace", name = "8" }
alt-F9 = { type = "show-workspace", name = "9" }
alt-F10 = { type = "show-workspace", name = "10" }
alt-F11 = { type = "show-workspace", name = "11" }
alt-F12 = { type = "show-workspace", name = "12" }
# The move-to-workspace action moves the currently focused window to a workspace.
alt-shift-F1 = { type = "move-to-workspace", name = "1" }
alt-shift-F2 = { type = "move-to-workspace", name = "2" }
alt-shift-F3 = { type = "move-to-workspace", name = "3" }
alt-shift-F4 = { type = "move-to-workspace", name = "4" }
alt-shift-F5 = { type = "move-to-workspace", name = "5" }
alt-shift-F6 = { type = "move-to-workspace", name = "6" }
alt-shift-F7 = { type = "move-to-workspace", name = "7" }
alt-shift-F8 = { type = "move-to-workspace", name = "8" }
alt-shift-F9 = { type = "move-to-workspace", name = "9" }
alt-shift-F10 = { type = "move-to-workspace", name = "10" }
alt-shift-F11 = { type = "move-to-workspace", name = "11" }
alt-shift-F12 = { type = "move-to-workspace", name = "12" }
When I started Jay via jay run and launched a foot terminal to run top, I saw a high amount of I/O wait and a constant 1% of CPU usage by the Jay process.
Log file: jay-2026-03-19T14:50:50.610Z-0.txt
The VM is configured to use OpenGL with 3D acceleration enabled:
Am guessing the high I/O wait is due to the virtualised hw being used and am just checking its not unexpected.