From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Linux PM <linux-pm@vger.kernel.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>,
Thomas Gleixner <tglx@linutronix.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH 1/4 v2] PM / suspend: Prevent might sleep splats
Date: Fri, 25 May 2018 17:54:41 +0200 [thread overview]
Message-ID: <20180525155440.jwqrpu3shocwcwjy@linutronix.de> (raw)
In-Reply-To: <CAJZ5v0j8zf36HdxH-YR_jTS02tF-BF3w7f9tLjf6UJoqCPG+mQ@mail.gmail.com>
From: Thomas Gleixner <tglx@linutronix.de>
timekeeping suspend/resume calls read_persistent_clock() which takes
rtc_lock. That results in might sleep warnings because at that point
we run with interrupts disabled.
We cannot convert rtc_lock to a raw spinlock as that would trigger
other might sleep warnings.
As a workaround we disable the might sleep warnings by setting
system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock
contention because hibernate / suspend to RAM is single-CPU at this
point.
In s2idle's case the system_state is set to SYSTEM_SUSPEND before
timekeeping_suspend() which is invoked by the last CPU. In the resume
case it set back to SYSTEM_RUNNING after timekeeping_resume() which is
invoked by the first CPU in the resume case. The other CPUs will block
on tick_freeze_lock.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: cover s2idle in tick_freeze() / tick_unfreeze()]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v1…v2: Moved the s2idle case into tick_freeze()/unfreeze() as suggested
by Rafael (tglx was okay with this).
include/linux/kernel.h | 1 +
kernel/power/hibernate.c | 7 +++++++
kernel/power/suspend.c | 4 ++++
kernel/time/tick-common.c | 2 ++
4 files changed, 14 insertions(+)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 6a1eb0b0aad9..7aed92624531 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -542,6 +542,7 @@ extern enum system_states {
SYSTEM_HALT,
SYSTEM_POWER_OFF,
SYSTEM_RESTART,
+ SYSTEM_SUSPEND,
} system_state;
/* This cannot be an enum because some may be used in assembly source. */
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 5454cc639a8d..9c85c7822383 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -287,6 +287,8 @@ static int create_image(int platform_mode)
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (error) {
pr_err("Some system devices failed to power down, aborting hibernation\n");
@@ -317,6 +319,7 @@ static int create_image(int platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -445,6 +448,7 @@ static int resume_target_kernel(bool platform_mode)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error)
@@ -478,6 +482,7 @@ static int resume_target_kernel(bool platform_mode)
syscore_resume();
Enable_irqs:
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
@@ -563,6 +568,7 @@ int hibernation_platform_enter(void)
goto Enable_cpus;
local_irq_disable();
+ system_state = SYSTEM_SUSPEND;
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
@@ -575,6 +581,7 @@ int hibernation_platform_enter(void)
Power_up:
syscore_resume();
+ system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4c10be0f4843..5149c77506b3 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -428,6 +428,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
arch_suspend_disable_irqs();
BUG_ON(!irqs_disabled());
+ system_state = SYSTEM_SUSPEND;
+
error = syscore_suspend();
if (!error) {
*wakeup = pm_wakeup_pending();
@@ -443,6 +445,8 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
syscore_resume();
}
+ system_state = SYSTEM_RUNNING;
+
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 49edc1c4f3e6..14de3727b18e 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -490,6 +490,7 @@ void tick_freeze(void)
if (tick_freeze_depth == num_online_cpus()) {
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), true);
+ system_state = SYSTEM_SUSPEND;
timekeeping_suspend();
} else {
tick_suspend_local();
@@ -513,6 +514,7 @@ void tick_unfreeze(void)
if (tick_freeze_depth == num_online_cpus()) {
timekeeping_resume();
+ system_state = SYSTEM_RUNNING;
trace_suspend_resume(TPS("timekeeping_freeze"),
smp_processor_id(), false);
} else {
--
2.17.0
next prev parent reply other threads:[~2018-05-25 15:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-25 9:46 PM / suspend / s2idle: avoiding splats on RT Sebastian Andrzej Siewior
2018-05-25 9:46 ` [PATCH 1/4] PM / suspend: Prevent might sleep splats Sebastian Andrzej Siewior
2018-05-25 10:03 ` Rafael J. Wysocki
2018-05-25 15:54 ` Sebastian Andrzej Siewior [this message]
2018-05-29 8:49 ` [PATCH 1/4 v2] " Rafael J. Wysocki
2018-05-25 9:46 ` [PATCH 2/4] PM / wakeup: Make events_lock a RAW_SPINLOCK Sebastian Andrzej Siewior
2018-05-25 9:46 ` [PATCH 3/4] PM / s2idle: Make s2idle_wait_head swait based Sebastian Andrzej Siewior
2018-05-25 9:46 ` [PATCH 4/4] PM / wakeup: Make s2idle_lock a RAW_SPINLOCK Sebastian Andrzej Siewior
2018-05-25 10:05 ` PM / suspend / s2idle: avoiding splats on RT Rafael J. Wysocki
2018-05-25 10:12 ` Sebastian Andrzej Siewior
2018-05-25 10:20 ` Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180525155440.jwqrpu3shocwcwjy@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=pavel@ucw.cz \
--cc=rafael@kernel.org \
--cc=rjw@rjwysocki.net \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).