[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <7813dff5-b140-48c4-bc15-ed25c7a07591@intel.com>
Date: Fri, 17 May 2024 11:48:44 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: Kalle Valo <kvalo@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>,
Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"Rafael J. Wysocki" <rafael@...nel.org>, x86@...nel.org,
linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
regressions@...ts.linux.dev, Jeff Johnson <quic_jjohnson@...cinc.com>
Subject: Re: [regression] suspend stress test stalls within 30 minutes
On 5/17/24 11:37, Kalle Valo wrote:
> While writing this email I found another way to continue the suspend
> after a stall: terminate rtcwake with CTRL-C in the ssh session running
> the for loop. That explains why 'sudo shutdown -h now' makes the suspend
> go forward, it most likely kills the stalled rtcwake process.
Could we try and figure out what rtcwake is doing during its stall? A
couple of ideas:
You could strace it to see if it's hung in the kernel:
strace -o strace.log rtcwake ... <args here>
You could look at its stack in /proc, like this:
# cat /proc/`pidof sleep`/stack
[<0>] hrtimer_nanosleep+0xb5/0x190
[<0>] common_nsleep+0x44/0x50
[<0>] __x64_sys_clock_nanosleep+0xcb/0x140
[<0>] do_syscall_64+0x65/0x140
[<0>] entry_SYSCALL_64_after_hwframe+0x6e/0x76
Or you can use sysrq:
echo t > /proc/sysrq-trigger
to get *all* tasks' stacks dumped out to dmesg.
I'd probably do all three in that order.
Getting a function-graph trace of rtcwake during the stall would also be
nice, but that's a lot of data so let's try the easier things first.
Powered by blists - more mailing lists