Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 48 insertions, 3 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index 13c0a1143f4..b663c2c95d3 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -44,6 +44,9 @@
 
 #include <asm/uaccess.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/printk.h>
+
 /*
  * Architectures can override it:
  */
@@ -542,6 +545,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to"
 static void _call_console_drivers(unsigned start,
 				unsigned end, int msg_log_level)
 {
+	trace_console(&LOG_BUF(0), start, end, log_buf_len);
+
 	if ((msg_log_level < console_loglevel || ignore_loglevel) &&
 			console_drivers && start != end) {
 		if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) {
@@ -702,6 +707,9 @@ static bool printk_time = 0;
 #endif
 module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
 
+static bool always_kmsg_dump;
+module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
+
 /* Check if we have any console registered that can be called early in boot. */
 static int have_callable_console(void)
 {
@@ -1208,13 +1216,27 @@ int is_console_locked(void)
 	return console_locked;
 }
 
+/*
+ * Delayed printk facility, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE		512
+
+#define PRINTK_PENDING_WAKEUP	0x01
+#define PRINTK_PENDING_SCHED	0x02
+
 static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
 
 void printk_tick(void)
 {
 	if (__this_cpu_read(printk_pending)) {
-		__this_cpu_write(printk_pending, 0);
-		wake_up_interruptible(&log_wait);
+		int pending = __this_cpu_xchg(printk_pending, 0);
+		if (pending & PRINTK_PENDING_SCHED) {
+			char *buf = __get_cpu_var(printk_sched_buf);
+			printk(KERN_WARNING "[sched_delayed] %s", buf);
+		}
+		if (pending & PRINTK_PENDING_WAKEUP)
+			wake_up_interruptible(&log_wait);
 	}
 }
 
@@ -1228,7 +1250,7 @@ int printk_needs_cpu(int cpu)
 void wake_up_klogd(void)
 {
 	if (waitqueue_active(&log_wait))
-		this_cpu_write(printk_pending, 1);
+		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
 }
 
 /**
@@ -1621,6 +1643,26 @@ late_initcall(printk_late_init);
 
 #if defined CONFIG_PRINTK
 
+int printk_sched(const char *fmt, ...)
+{
+	unsigned long flags;
+	va_list args;
+	char *buf;
+	int r;
+
+	local_irq_save(flags);
+	buf = __get_cpu_var(printk_sched_buf);
+
+	va_start(args, fmt);
+	r = vsnprintf(buf, PRINTK_BUF_SIZE, fmt, args);
+	va_end(args);
+
+	__this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+	local_irq_restore(flags);
+
+	return r;
+}
+
 /*
  * printk rate limiting, lifted from the networking subsystem.
  *
@@ -1732,6 +1774,9 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 	unsigned long l1, l2;
 	unsigned long flags;
 
+	if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
+		return;
+
 	/* Theoretically, the log could move on after we do this, but
 	   there's not a lot we can do about that. The new messages
 	   will overwrite the start of what we dump. */