Merge tag 'y2038' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground into timers/core

Pull more y2038 work from Arnd Bergman:

y2038: convert more syscalls

Here is another set of system call changes to prepare the change over to
64-bit time_t. As before, the strategy is to change system calls that
take a 'struct timespec' argument over to 'struct __kernel_timespec',
which for now is defined to be the same but will get redefined to use a
64-bit time_t argument once we are ready to modify the system call tables.

The major change from previous patches is that the plan is no longer
to directly use the 'compat' system calls for providing compatibility
with the existing 32-bit time_t based entry points. Instead, we rename
the compat code to something that makes more sense on 32-bit architectures,
e.g. compat_timespec becomes old_timespec32.

With the renamed types in place, change over the 'stat' and 'utimes'
families of system calls, sched_rr_get_interval, recvmmsg and
rt_sigtimedwait. Another series for poll, select and io_pgetevents is
currently being tested.

1 files changed, 14 insertions, 1 deletions

diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 32b479468e4d..b9132d1269ef 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -40,6 +40,11 @@ int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
  */
 unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
 
+/*
+ * Zero (default value) means use sysctl_hung_task_timeout_secs:
+ */
+unsigned long __read_mostly sysctl_hung_task_check_interval_secs;
+
 int __read_mostly sysctl_hung_task_warnings = 10;
 
 static int __read_mostly did_panic;
@@ -98,8 +103,11 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 
 	if (switch_count != t->last_switch_count) {
 		t->last_switch_count = switch_count;
+		t->last_switch_time = jiffies;
 		return;
 	}
+	if (time_is_after_jiffies(t->last_switch_time + timeout * HZ))
+		return;
 
 	trace_sched_process_hang(t);
 
@@ -245,8 +253,13 @@ static int watchdog(void *dummy)
 
 	for ( ; ; ) {
 		unsigned long timeout = sysctl_hung_task_timeout_secs;
-		long t = hung_timeout_jiffies(hung_last_checked, timeout);
+		unsigned long interval = sysctl_hung_task_check_interval_secs;
+		long t;
 
+		if (interval == 0)
+			interval = timeout;
+		interval = min_t(unsigned long, interval, timeout);
+		t = hung_timeout_jiffies(hung_last_checked, interval);
 		if (t <= 0) {
 			if (!atomic_xchg(&reset_hung_task, 0))
 				check_hung_uninterruptible_tasks(timeout);