From: John Ogness <john.ogness@linutronix.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andrea Parri <parri.andrea@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Paul McKenney <paulmck@kernel.org>,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH v5 3/4] Revert "printk: lock/unlock console only for new logbuf entries"
Date: Thu, 9 Jul 2020 15:29:43 +0206 [thread overview]
Message-ID: <20200709132344.760-4-john.ogness@linutronix.de> (raw)
In-Reply-To: <20200709132344.760-1-john.ogness@linutronix.de>
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>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
---
kernel/printk/printk.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index b71eaf5f5a86..1b41e1b98221 100644
--- 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);
--
2.20.1
next prev parent reply other threads:[~2020-07-09 13:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 13:23 [PATCH v5 0/4] printk: replace ringbuffer John Ogness
2020-07-09 13:23 ` [PATCH v5 1/4] crash: add VMCOREINFO macro to define offset in a struct declared by typedef John Ogness
2020-07-09 13:23 ` [PATCH v5 2/4] printk: add lockless ringbuffer John Ogness
2020-07-10 8:43 ` Sergey Senozhatsky
2020-07-10 8:47 ` Sergey Senozhatsky
2020-07-09 13:23 ` John Ogness [this message]
2020-07-09 13:23 ` [PATCH v5 4/4] printk: use the " John Ogness
2020-07-14 5:26 ` [printk] 96d5c61b1f: stress-ng.timerfd.ops_per_sec 8.3% improvement kernel test robot
2020-07-18 12:10 ` [PATCH v5 4/4] printk: use the lockless ringbuffer Marco Elver
2020-07-19 3:43 ` Sergey Senozhatsky
2020-07-20 6:43 ` Marco Elver
2020-07-20 8:22 ` Andy Shevchenko
2020-07-20 8:34 ` Sergey Senozhatsky
2020-07-20 8:41 ` Sergey Senozhatsky
2020-07-20 9:40 ` Marco Elver
2020-07-20 10:01 ` Dmitry Vyukov
2020-07-20 10:20 ` John Ogness
2020-07-20 10:32 ` Marco Elver
2020-08-11 20:47 ` Nick Desaulniers
2020-08-12 16:40 ` John Ogness
2021-01-22 23:52 ` Issue in dmesg time with lockless ring buffer J. Avila
2021-01-25 13:32 ` John Ogness
2021-01-26 0:00 ` J. Avila
2021-01-29 1:46 ` J. Avila
2020-07-10 8:28 ` [PATCH v5 0/4] printk: replace ringbuffer Petr Mladek
2020-07-13 2:23 ` Sergey Senozhatsky
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