From: John Ogness <[email protected]>
[ Upstream commit d01ff281bd9b1bfeac9ab98ec8a9ee41da900d5e ]
Currently printk_trigger_flush() only triggers legacy offloaded
flushing, even if that may not be the appropriate method to flush
for currently registered consoles. (The function predates the
NBCON consoles.)
Since commit 6690d6b52726 ("printk: Add helper for flush type
logic") there is printk_get_console_flush_type(), which also
considers NBCON consoles and reports all the methods of flushing
appropriate based on the system state and consoles available.
Update printk_trigger_flush() to use
printk_get_console_flush_type() to appropriately flush registered
consoles.
Suggested-by: Petr Mladek <[email protected]>
Signed-off-by: John Ogness <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Link:
https://lore.kernel.org/stable/20251113160351.113031-2-john.ogness%40linutronix.de
Tested-by: Sherry Sun <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
---
kernel/printk/nbcon.c | 2 +-
kernel/printk/printk.c | 23 ++++++++++++++++++++++-
2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c
index e7a3af81b173..4d23305689e9 100644
--- a/kernel/printk/nbcon.c
+++ b/kernel/printk/nbcon.c
@@ -1827,7 +1827,7 @@ void nbcon_device_release(struct console *con)
if (console_trylock())
console_unlock();
} else if (ft.legacy_offload) {
- printk_trigger_flush();
+ defer_console_output();
}
}
console_srcu_read_unlock(cookie);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3a91b739e8f3..178d4b46736c 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -4539,9 +4539,30 @@ void defer_console_output(void)
__wake_up_klogd(PRINTK_PENDING_WAKEUP | PRINTK_PENDING_OUTPUT);
}
+/**
+ * printk_trigger_flush - Attempt to flush printk buffer to consoles.
+ *
+ * If possible, flush the printk buffer to all consoles in the caller's
+ * context. If offloading is available, trigger deferred printing.
+ *
+ * This is best effort. Depending on the system state, console states,
+ * and caller context, no actual flushing may result from this call.
+ */
void printk_trigger_flush(void)
{
- defer_console_output();
+ struct console_flush_type ft;
+
+ printk_get_console_flush_type(&ft);
+ if (ft.nbcon_atomic)
+ nbcon_atomic_flush_pending();
+ if (ft.nbcon_offload)
+ nbcon_kthreads_wake();
+ if (ft.legacy_direct) {
+ if (console_trylock())
+ console_unlock();
+ }
+ if (ft.legacy_offload)
+ defer_console_output();
}
int vprintk_deferred(const char *fmt, va_list args)
--
2.49.1
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#16261):
https://lists.yoctoproject.org/g/linux-yocto/message/16261
Mute This Topic: https://lists.yoctoproject.org/mt/117611993/21656
Group Owner: [email protected]
Unsubscribe: https://lists.yoctoproject.org/g/linux-yocto/unsub
[[email protected]]
-=-=-=-=-=-=-=-=-=-=-=-
