From 6bd1b4d35c05c21a78bf00f610587ce8a75cb5c2 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Roger=20Pau=20Monn=C3=A9?= Date: Fri, 18 Feb 2022 09:02:16 +0100 Subject: [PATCH] x86/console: process softirqs between warning prints MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Process softirqs while printing end of boot warnings. Each warning can be several lines long, and on slow consoles printing multiple ones without processing softirqs can result in the watchdog triggering: (XEN) [ 22.277806] *************************************************** (XEN) [ 22.417802] WARNING: CONSOLE OUTPUT IS SYNCHRONOUS (XEN) [ 22.556029] This option is intended to aid debugging of Xen by ensuring (XEN) [ 22.696802] that all output is synchronously delivered on the serial line. (XEN) [ 22.838024] However it can introduce SIGNIFICANT latencies and affect (XEN) [ 22.978710] timekeeping. It is NOT recommended for production use! (XEN) [ 23.119066] *************************************************** (XEN) [ 23.258865] Booted on L1TF-vulnerable hardware with SMT/Hyperthreading (XEN) [ 23.399560] enabled. Please assess your configuration and choose an (XEN) [ 23.539925] explicit 'smt=' setting. See XSA-273. (XEN) [ 23.678860] *************************************************** (XEN) [ 23.818492] Booted on MLPDS/MFBDS-vulnerable hardware with SMT/Hyperthreading (XEN) [ 23.959811] enabled. Mitigations will not be fully effective. Please (XEN) [ 24.100396] choose an explicit smt= setting. See XSA-297. (XEN) [ 24.240254] *************************************************(XEN) [ 24.247302] Watchdog timer detects that CPU0 is stuck! (XEN) [ 24.386785] ----[ Xen-4.17-unstable x86_64 debug=y Tainted: C ]---- (XEN) [ 24.527874] CPU: 0 (XEN) [ 24.662422] RIP: e008:[] drivers/char/ns16550.c#ns16550_tx_ready+0x3a/0x90 Fixes: ee3fd57acd ('xen: add warning infrastructure') Signed-off-by: Roger Pau Monné Acked-by: Jan Beulich --- xen/common/warning.c | 1 + 1 file changed, 1 insertion(+) diff --git a/xen/common/warning.c b/xen/common/warning.c index 0269c6715c..e6e1404baf 100644 --- a/xen/common/warning.c +++ b/xen/common/warning.c @@ -30,6 +30,7 @@ void __init warning_print(void) { printk("%s", warnings[i]); printk("***************************************************\n"); + process_pending_softirqs(); } for ( i = 0; i < 3; i++ ) -- 2.30.2