From: Thomas Gleixner <tglx@linutronix.de>
To: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Frederic Weisbecker <frederic@kernel.org>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Grygorii Strashko <grygorii.strashko@ti.com>
Subject: Re: Fix 80d20d35af1e ("nohz: Fix local_timer_softirq_pending()") may have revealed another problem
Date: Fri, 24 Aug 2018 10:01:35 +0200 (CEST) [thread overview]
Message-ID: <alpine.DEB.2.21.1808241000340.1668@nanos.tec.linutronix.de> (raw)
In-Reply-To: <67ce38dc-1f00-55c6-f9ae-2dec00172cf6@gmail.com>
On Fri, 24 Aug 2018, Heiner Kallweit wrote:
> On 24.08.2018 06:12, Frederic Weisbecker wrote:
> > On Thu, Aug 16, 2018 at 08:13:03AM +0200, Heiner Kallweit wrote:
> >> Recently I started to get warning "NOHZ: local_softirq_pending 202" and
> >> I think it's related to mentioned commit (didn't bisect it yet).
> >> See log from suspending.
> >>
> >> I have no reason to think the fix is wrong, it may just have revealed
> >> another issue which existed before and was hidden by the bug.
> >>
> >> Rgds, Heiner
> >>
> >> [ 75.073353] random: crng init done
> >> [ 75.073402] random: 7 urandom warning(s) missed due to ratelimiting
> >> [ 78.619564] PM: suspend entry (deep)
> >> [ 78.619675] PM: Syncing filesystems ... done.
> >> [ 78.653684] Freezing user space processes ... (elapsed 0.002 seconds) done.
> >> [ 78.656094] OOM killer disabled.
> >> [ 78.656113] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> >> [ 78.658177] Suspending console(s) (use no_console_suspend to debug)
> >> [ 78.663066] nuvoton-cir 00:07: disabled
> >> [ 78.671817] sd 0:0:0:0: [sda] Synchronizing SCSI cache
> >> [ 78.672210] sd 0:0:0:0: [sda] Stopping disk
> >> [ 78.786651] ACPI: Preparing to enter system sleep state S3
> >> [ 78.789613] PM: Saving platform NVS memory
> >> [ 78.789759] Disabling non-boot CPUs ...
> >> [ 78.805154] NOHZ: local_softirq_pending 202
> >> [ 78.805182] NOHZ: local_softirq_pending 202
> >> [ 78.807102] smpboot: CPU 1 is now offline
> >
> > I've tried to reproduce with suspend on disk but got unsuccessful.
> >
> > A small question as I see someone is having a similar issue with a stable
> > release only. On which kernel did you trigger that: upstream or stable?
> >
> > I'll continue investigating.
> >
> > Thanks.
> >
> Affected is recent linux-next, after the commit mentioned in the subject.
> I can work around the warning (not sure whether it's a proper fix),
> see here:
> https://lkml.org/lkml/2018/8/18/272
Can you try the one I posted in this thread:
https://lkml.kernel.org/r/alpine.DEB.2.21.1808240851420.1668@nanos.tec.linutronix.de
Also below for reference.
Thanks,
tglx
8<----------------
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5b33e2f5c0ed..6aab9d54a331 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -888,7 +888,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
if (unlikely(local_softirq_pending() && cpu_online(cpu))) {
static int ratelimit;
- if (ratelimit < 10 &&
+ if (ratelimit < 10 && !in_softirq() &&
(local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) {
pr_warn("NOHZ: local_softirq_pending %02x\n",
(unsigned int) local_softirq_pending());
next prev parent reply other threads:[~2018-08-24 8:01 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-16 6:13 Fix 80d20d35af1e ("nohz: Fix local_timer_softirq_pending()") may have revealed another problem Heiner Kallweit
2018-08-18 11:26 ` Thomas Gleixner
2018-08-18 22:34 ` Heiner Kallweit
2018-08-24 4:12 ` Frederic Weisbecker
2018-08-24 5:59 ` Heiner Kallweit
2018-08-24 8:01 ` Thomas Gleixner [this message]
2018-08-24 14:30 ` Frederic Weisbecker
2018-08-24 17:06 ` Heiner Kallweit
2018-08-28 2:25 ` Frederic Weisbecker
2018-09-27 16:05 ` Thomas Gleixner
2018-09-28 13:18 ` Frederic Weisbecker
2018-09-28 20:35 ` Heiner Kallweit
2018-10-15 20:58 ` Heiner Kallweit
2018-12-24 21:11 ` Heiner Kallweit
2018-12-27 6:53 ` Frederic Weisbecker
2018-12-27 23:11 ` Heiner Kallweit
2018-12-28 1:31 ` Frederic Weisbecker
2018-12-28 6:34 ` Heiner Kallweit
2018-12-28 6:39 ` Heiner Kallweit
2019-01-09 22:20 ` Heiner Kallweit
2019-01-11 21:36 ` Frederic Weisbecker
2019-01-16 6:24 ` Frederic Weisbecker
2019-01-16 18:42 ` Heiner Kallweit
2019-01-24 19:37 ` Heiner Kallweit
2019-02-14 19:05 ` Heiner Kallweit
2019-02-14 21:47 ` Thomas Gleixner
2019-02-14 22:33 ` Heiner Kallweit
2019-02-15 0:31 ` Frederic Weisbecker
2019-02-16 9:14 ` Heiner Kallweit
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