Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751791AbbEYMsc (ORCPT ); Mon, 25 May 2015 08:48:32 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53616 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751418AbbEYMrE (ORCPT ); Mon, 25 May 2015 08:47:04 -0400 From: Petr Mladek To: Andrew Morton Cc: Frederic Weisbecker , Steven Rostedt , Dave Anderson , "Paul E. McKenney" , Kay Sievers , Jiri Kosina , Michal Hocko , Jan Kara , linux-kernel@vger.kernel.org, Wang Long , peifeiyue@huawei.com, dzickus@redhat.com, morgan.wang@huawei.com, sasha.levin@oracle.com, Petr Mladek Subject: [PATCH 06/10] printk: Split delayed printing of warnings from vprintk_emit() Date: Mon, 25 May 2015 14:46:29 +0200 Message-Id: <1432557993-20458-7-git-send-email-pmladek@suse.cz> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1432557993-20458-1-git-send-email-pmladek@suse.cz> References: <1432557993-20458-1-git-send-email-pmladek@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3649 Lines: 118 printk_emit() is too long. Let's split the delayed printing of warnings into a separate function. This patch just shuffles the code. There is no change in the functionality. Signed-off-by: Petr Mladek --- kernel/printk/printk.c | 64 +++++++++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 24 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 8fb0aaaa6258..91b8043044ac 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -233,6 +233,9 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock); DECLARE_WAIT_QUEUE_HEAD(log_wait); /* cpu currently holding logbuf_lock */ static unsigned int logbuf_cpu = UINT_MAX; +/* flags used for delayed printing of warnings */ +static int recursion_bug; +static atomic_t nmi_message_lost; /* the next printk record to read by syslog(READ) or /proc/kmsg */ static u64 syslog_seq; static u32 syslog_idx; @@ -269,6 +272,8 @@ static u32 clear_idx; static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); static char *log_buf = __log_buf; static u32 log_buf_len = __LOG_BUF_LEN; +/* helper buffer to print formatted text */ +static char textbuf[LOG_LINE_MAX]; /* Return log buffer address */ char *log_buf_addr_get(void) @@ -1701,13 +1706,44 @@ static int try_logbuf_lock_in_nmi(void) return 0; } +/* + * This function modifies the global textbuf and therefore it must be called + * under lockbuf_lock! + */ +static int vprintk_delayed_warnings(void) +{ + int printed_len = 0; + int text_len; + + if (unlikely(recursion_bug)) { + static const char recursion_msg[] = + "BUG: recent printk recursion!"; + + recursion_bug = 0; + /* emit KERN_CRIT message */ + printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, + NULL, 0, recursion_msg, + strlen(recursion_msg)); + } + + if (unlikely(atomic_read(&nmi_message_lost))) { + int lost = atomic_xchg(&nmi_message_lost, 0); + + text_len = scnprintf(textbuf, sizeof(textbuf), + "BAD LUCK: lost %d message(s) from NMI context!", + lost); + /* emit KERN_CRIT message */ + printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, + NULL, 0, textbuf, text_len); + } + + return printed_len; +} + asmlinkage int vprintk_emit(int facility, int level, const char *dict, size_t dictlen, const char *fmt, va_list args) { - static int recursion_bug; - static atomic_t nmi_message_lost; - static char textbuf[LOG_LINE_MAX]; char *text = textbuf; size_t text_len = 0; enum log_flags lflags = 0; @@ -1770,27 +1806,7 @@ asmlinkage int vprintk_emit(int facility, int level, logbuf_cpu = this_cpu; - if (unlikely(recursion_bug)) { - static const char recursion_msg[] = - "BUG: recent printk recursion!"; - - recursion_bug = 0; - /* emit KERN_CRIT message */ - printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, - NULL, 0, recursion_msg, - strlen(recursion_msg)); - } - - if (unlikely(atomic_read(&nmi_message_lost))) { - int lost = atomic_xchg(&nmi_message_lost, 0); - - text_len = scnprintf(text, sizeof(textbuf), - "BAD LUCK: lost %d message(s) from NMI context!", - lost); - /* emit KERN_CRIT message */ - printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, - NULL, 0, text, text_len); - } + printed_len += vprintk_delayed_warnings(); /* * The printf needs to come first; we need the syslog -- 1.8.5.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/