Testing on a Kaby Lake box with 8 CPUs leads to the serial buffer being filled halfway during dom0 boot, and thus a non-trivial chunk of Linux boot messages are dropped.
Increasing the buffer to 128K does fix the issue and Linux boot messages are no longer dropped. There's no justification either on why 16K was chosen, and hence bumping to 128K in order to cope with current systems generating output faster does seem appropriate to have a better user experience with the provided defaults. Signed-off-by: Roger Pau Monné <[email protected]> -- Changes since v2: - Bump to 128K. --- xen/drivers/char/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index 06350c387371..1cd9cddfe1bf 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -77,13 +77,13 @@ config HAS_EHCI config SERIAL_TX_BUFSIZE int "Size of the transmit serial buffer" - default 16384 + default 131072 help Controls the default size of the transmit buffer (in bytes) used by the serial driver. Note the value provided will be rounded down to the nearest power of 2. - Default value is 16384 (16kiB). + Default value is 131072 (128KiB). config XHCI bool "XHCI DbC UART driver" -- 2.42.0
