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author | Thomas Gleixner <tglx@linutronix.de> | 2017-10-03 16:39:02 +0200 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2017-10-04 10:53:54 +0200 |
commit | 34ddaa3e5c0096fef52485186c7eb6cf56ddc686 (patch) | |
tree | 3d98dfe007218f46a0b9b287fb2fe58b4797a9d5 /Documentation/sysctl | |
parent | e31d6883f21c1cdfe5bc64e28411f8a92b783fde (diff) | |
download | linux-34ddaa3e5c0096fef52485186c7eb6cf56ddc686.tar.gz linux-34ddaa3e5c0096fef52485186c7eb6cf56ddc686.tar.bz2 linux-34ddaa3e5c0096fef52485186c7eb6cf56ddc686.zip |
powerpc/watchdog: Make use of watchdog_nmi_probe()
The rework of the core hotplug code triggers the WARN_ON in start_wd_cpu()
on powerpc because it is called multiple times for the boot CPU.
The first call is via:
start_wd_on_cpu+0x80/0x2f0
watchdog_nmi_reconfigure+0x124/0x170
softlockup_reconfigure_threads+0x110/0x130
lockup_detector_init+0xbc/0xe0
kernel_init_freeable+0x18c/0x37c
kernel_init+0x2c/0x160
ret_from_kernel_thread+0x5c/0xbc
And then again via the CPU hotplug registration:
start_wd_on_cpu+0x80/0x2f0
cpuhp_invoke_callback+0x194/0x620
cpuhp_thread_fun+0x7c/0x1b0
smpboot_thread_fn+0x290/0x2a0
kthread+0x168/0x1b0
ret_from_kernel_thread+0x5c/0xbc
This can be avoided by setting up the cpu hotplug state with nocalls and
move the initialization to the watchdog_nmi_probe() function. That
initializes the hotplug callbacks without invoking the callback and the
following core initialization function then configures the watchdog for the
online CPUs (in this case CPU0) via softlockup_reconfigure_threads().
Reported-and-tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Diffstat (limited to 'Documentation/sysctl')
0 files changed, 0 insertions, 0 deletions