Revert "printk: lock/unlock console only for new logbuf entries"

This reverts commit 3ac37a93fa9217e576bebfd4ba3e80edaaeb2289.

This optimization will not apply once the transition to a lockless
printk is complete. Rather than porting this optimization through
the transition only to remove it anyway, just revert it now to
simplify the transition.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200709132344.760-4-john.ogness@linutronix.de

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index b71eaf5..1b41e1b 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1981,9 +1981,8 @@ asmlinkage int vprintk_emit(int facility, int level,
                            const char *fmt, va_list args)
 {
        int printed_len;
-       bool in_sched = false, pending_output;
+       bool in_sched = false;
        unsigned long flags;
-       u64 curr_log_seq;
 
        /* Suppress unimportant messages after panic happens */
        if (unlikely(suppress_printk))
@@ -1999,13 +1998,11 @@ asmlinkage int vprintk_emit(int facility, int level,
 
        /* This stops the holder of console_sem just where we want him */
        logbuf_lock_irqsave(flags);
-       curr_log_seq = log_next_seq;
        printed_len = vprintk_store(facility, level, dict, dictlen, fmt, args);
-       pending_output = (curr_log_seq != log_next_seq);
        logbuf_unlock_irqrestore(flags);
 
        /* If called from the scheduler, we can not call up(). */
-       if (!in_sched && pending_output) {
+       if (!in_sched) {
                /*
                 * Disable preemption to avoid being preempted while holding
                 * console_sem which would prevent anyone from printing to
@@ -2022,8 +2019,7 @@ asmlinkage int vprintk_emit(int facility, int level,
                preempt_enable();
        }
 
-       if (pending_output)
-               wake_up_klogd();
+       wake_up_klogd();
        return printed_len;
 }
 EXPORT_SYMBOL(vprintk_emit);