From: Rafael J. Wysocki rafael.j.wysocki@intel.com
commit a449dfbfc0894676ad0aa1873383265047529e3a upstream.
Using pr_cont() in the tasks freezing code related to system-wide suspend and hibernation is problematic, because the continuation messages printed there are susceptible to interspersing with other unrelated messages which results in output that is hard to understand.
Address this issue by modifying try_to_freeze_tasks() to print messages that don't require continuations and adjusting its callers accordingly.
Reported-by: Thomas Weißschuh linux@weissschuh.net Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Petr Mladek pmladek@suse.com Cc: Paul Menzel pmenzel@molgen.mpg.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/power/process.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)
--- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -27,6 +27,8 @@ unsigned int __read_mostly freeze_timeou
static int try_to_freeze_tasks(bool user_only) { + const char *what = user_only ? "user space processes" : + "remaining freezable tasks"; struct task_struct *g, *p; unsigned long end_time; unsigned int todo; @@ -36,6 +38,8 @@ static int try_to_freeze_tasks(bool user bool wakeup = false; int sleep_usecs = USEC_PER_MSEC;
+ pr_info("Freezing %s\n", what); + start = ktime_get_boottime();
end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs); @@ -82,7 +86,6 @@ static int try_to_freeze_tasks(bool user elapsed_msecs = ktime_to_ms(elapsed);
if (todo) { - pr_cont("\n"); pr_err("Freezing of tasks %s after %d.%03d seconds " "(%d tasks refusing to freeze, wq_busy=%d):\n", wakeup ? "aborted" : "failed", @@ -101,8 +104,8 @@ static int try_to_freeze_tasks(bool user read_unlock(&tasklist_lock); } } else { - pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000, - elapsed_msecs % 1000); + pr_info("Freezing %s completed (elapsed %d.%03d seconds)\n", + what, elapsed_msecs / 1000, elapsed_msecs % 1000); }
return todo ? -EBUSY : 0; @@ -130,14 +133,11 @@ int freeze_processes(void) static_branch_inc(&freezer_active);
pm_wakeup_clear(0); - pr_info("Freezing user space processes ... "); pm_freezing = true; error = try_to_freeze_tasks(true); - if (!error) { + if (!error) __usermodehelper_set_disable_depth(UMH_DISABLED); - pr_cont("done."); - } - pr_cont("\n"); + BUG_ON(in_atomic());
/* @@ -166,14 +166,9 @@ int freeze_kernel_threads(void) { int error;
- pr_info("Freezing remaining freezable tasks ... "); - pm_nosig_freezing = true; error = try_to_freeze_tasks(false); - if (!error) - pr_cont("done.");
- pr_cont("\n"); BUG_ON(in_atomic());
if (error)