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From: Petr Mladek <pmladek@suse.cz>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Dave Anderson <anderson@redhat.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Kay Sievers <kay@vrfy.org>, Jiri Kosina <jkosina@suse.cz>,
	Michal Hocko <mhocko@suse.cz>, Jan Kara <jack@suse.cz>,
	linux-kernel@vger.kernel.org,
	Wang Long <long.wanglong@huawei.com>,
	peifeiyue@huawei.com, dzickus@redhat.com, morgan.wang@huawei.com,
	sasha.levin@oracle.com, Petr Mladek <pmladek@suse.cz>
Subject: [PATCH 08/10] printk: Detect scheduler messages in vprintk_format_and_analyze()
Date: Mon, 25 May 2015 14:46:31 +0200	[thread overview]
Message-ID: <1432557993-20458-9-git-send-email-pmladek@suse.cz> (raw)
In-Reply-To: <1432557993-20458-1-git-send-email-pmladek@suse.cz>

The special hack for messages printed by the scheduler belongs to
the new vprintk_format_and_analyze().

This patch just shuffles the code. There is no change in
the functionality.

Signed-off-by: Petr Mladek <pmladek@suse.cz>
---
 kernel/printk/printk.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 7d009144f97f..6e53b6f60ca3 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1747,15 +1747,16 @@ static int vprintk_delayed_warnings(void)
  * @dict: pointer to the message dictionary
  * @facility: syslog facility
  * @level: syslog level; might be replaced by the one found in the fomatted text
+ * @in_sched: is set to true when the message is printed by the scheduler
  * @ftext: pointer to the formatted text after the syslog prefix
  * @ftext_len: length of the formatted text without the syslog prefix
  *
  * This function modifies the global textbuf and therefore it must be called
  * under lockbuf_lock!
  */
-static enum log_flags vprinkt_format_and_analyze(const char *fmt, va_list args,
+static enum log_flags vprintk_format_and_analyze(const char *fmt, va_list args,
 						 const char *dict, int facility,
-						 int *level,
+						 int *level, bool *in_sched,
 						 char **ftext,
 						 size_t *ftext_len)
 {
@@ -1775,6 +1776,15 @@ static enum log_flags vprinkt_format_and_analyze(const char *fmt, va_list args,
 		lflags |= LOG_NEWLINE;
 	}
 
+	/*
+	 * Messages printed by the scheduler must not wake up the console.
+	 * They are detected via a special @level, see printk_deferred().
+	 */
+	if (*level == LOGLEVEL_SCHED) {
+		*level = LOGLEVEL_DEFAULT;
+		*in_sched = true;
+	}
+
 	/* strip kernel syslog prefix and extract log level or control flags */
 	if (facility == 0) {
 		int kern_level = printk_get_level(text);
@@ -1824,11 +1834,6 @@ asmlinkage int vprintk_emit(int facility, int level,
 	int printed_len = 0;
 	bool in_sched = false;
 
-	if (level == LOGLEVEL_SCHED) {
-		level = LOGLEVEL_DEFAULT;
-		in_sched = true;
-	}
-
 	boot_delay_msec(level);
 	printk_delay();
 
@@ -1880,8 +1885,8 @@ asmlinkage int vprintk_emit(int facility, int level,
 
 	printed_len += vprintk_delayed_warnings();
 
-	lflags = vprinkt_format_and_analyze(fmt, args, dict, facility,
-					    &level,
+	lflags = vprintk_format_and_analyze(fmt, args, dict, facility,
+					    &level, &in_sched,
 					    &text, &text_len);
 
 	if (!(lflags & LOG_NEWLINE)) {
-- 
1.8.5.6


  parent reply	other threads:[~2015-05-25 12:47 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-25 12:46 [PATCH 00/10] printk: Avoid deadlock in NMI + vprintk_emit() cleanup Petr Mladek
2015-05-25 12:46 ` [PATCH 01/10] printk: Avoid deadlock in NMI context Petr Mladek
2015-05-27 23:13   ` Andrew Morton
2015-05-28 12:00     ` Petr Mladek
2015-05-25 12:46 ` [PATCH 02/10] printk: Try harder to get logbuf_lock on NMI Petr Mladek
2015-05-27 23:14   ` Andrew Morton
2015-05-28  7:54     ` Jiri Kosina
2015-05-28 13:50     ` Petr Mladek
2015-05-28 20:09       ` Andrew Morton
2015-05-29 10:56         ` Petr Mladek
2015-05-29 20:46           ` Andrew Morton
2015-05-25 12:46 ` [PATCH 03/10] printk: Move the deferred printk stuff Petr Mladek
2015-05-25 12:46 ` [PATCH 04/10] printk: Merge and flush NMI buffer predictably via IRQ work Petr Mladek
2015-05-27 23:14   ` Andrew Morton
2015-05-28 13:12     ` Petr Mladek
2015-05-25 12:46 ` [PATCH 05/10] printk: Try hard to print Oops message in NMI context Petr Mladek
2015-05-25 12:46 ` [PATCH 06/10] printk: Split delayed printing of warnings from vprintk_emit() Petr Mladek
2015-05-25 12:46 ` [PATCH 07/10] printk: Split text formatting and analyze " Petr Mladek
2015-05-25 12:46 ` Petr Mladek [this message]
2015-05-25 12:46 ` [PATCH 09/10] printk: Split text storing logic " Petr Mladek
2015-05-25 12:46 ` [PATCH 10/10] printk: Split console call " Petr Mladek
2015-05-29 20:50 ` [PATCH 00/10] printk: Avoid deadlock in NMI + vprintk_emit() cleanup Andrew Morton
2015-06-01 13:06   ` Jan Kara
2015-06-02  9:46     ` long.wanglong
2015-06-02  9:52       ` Jiri Kosina

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