From 6d4773a777a5a67e6b532e18a063bdabbe8616c9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 11 Sep 2023 16:01:49 +0000 Subject: [PATCH 130/184] printk: nbcon: Add nbcon console flushing using write_atomic() Perform nbcon console flushing at key call sites: console_flush_on_panic() - This function is not only used in panic() but also other locations where there may be stored messages that need to be flushed. Flush the nbcon consoles as well. printk_trigger_flush() - Used in urgent situations to trigger a dump in an irq_work context. For nbcon consoles, flush using the write_atomic() callback directly in the calling context since an alternative context is not required. Co-developed-by: John Ogness Signed-off-by: John Ogness Signed-off-by: Thomas Gleixner (Intel) Signed-off-by: Sebastian Andrzej Siewior --- kernel/printk/printk.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 4624c9d92a9d..8060d8a88fed 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3195,6 +3195,9 @@ void console_flush_on_panic(enum con_flush_mode mode) console_srcu_read_unlock(cookie); } + if (!have_boot_console) + nbcon_atomic_flush_all(); + console_flush_all(false, &next_seq, &handover); } @@ -3963,8 +3966,22 @@ void defer_console_output(void) __wake_up_klogd(PRINTK_PENDING_WAKEUP | PRINTK_PENDING_OUTPUT); } +/** + * printk_trigger_flush() - Make sure that the consoles will get flushed + * + * Try to flush consoles when possible or queue flushing consoles like + * in the deferred printk. + * + * Context: Can be used in any context + */ void printk_trigger_flush(void) { + if (!have_boot_console) { + preempt_disable(); + nbcon_atomic_flush_all(); + preempt_enable(); + } + defer_console_output(); } -- 2.34.1