This is a note to let you know that I've just added the patch titled
PM: sleep: Avoid using pr_cont() in the tasks freezing code
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pm-sleep-avoid-using-pr_cont-in-the-tasks-freezing-code.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a449dfbfc0894676ad0aa1873383265047529e3a Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Date: Thu, 1 Dec 2022 19:33:09 +0100
Subject: PM: sleep: Avoid using pr_cont() in the tasks freezing code
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From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Cc: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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)
Patches currently in stable-queue which might be from rafael.j.wysocki@xxxxxxxxx are
queue-6.1/pm-sleep-avoid-using-pr_cont-in-the-tasks-freezing-code.patch
