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

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This reverts commit 3ac37a93fa.

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
This commit is contained in:
John Ogness 2020-07-09 15:29:43 +02:06 committed by Petr Mladek
parent b6cf8b3f33
commit 8749efc0c0
1 changed files with 3 additions and 7 deletions
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10
kernel/printk/printk.c
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@ -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);