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| author | Nicholas Piggin <npiggin@gmail.com> | 2017-09-29 13:29:39 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-25 14:26:28 +0100 |
| commit | fa21a13d76a7eed4b1df1a5223752051dbfde948 (patch) | |
| tree | de958e4ce81edc11e6b1ea3dba240ba29726f669 | |
| parent | 97f41b41c432e5a80c91445d92c2f4b729984d36 (diff) | |
| download | linux-fa21a13d76a7eed4b1df1a5223752051dbfde948.tar.gz linux-fa21a13d76a7eed4b1df1a5223752051dbfde948.tar.bz2 linux-fa21a13d76a7eed4b1df1a5223752051dbfde948.zip | |
powerpc/watchdog: Do not trigger SMP crash from touch_nmi_watchdog
[ Upstream commit 80e4d70b06863e0104e5a0dc78aa3710297fbd4b ]
In xmon, touch_nmi_watchdog() is not expected to be checking that
other CPUs have not touched the watchdog, so the code will just call
touch_nmi_watchdog() once before re-enabling hard interrupts.
Just update our CPU's state, and ignore apparently stuck SMP threads.
Arguably touch_nmi_watchdog should check for SMP lockups, and callers
should be fixed, but that's not trivial for the input code of xmon.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kernel/watchdog.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index 57190f384f63..ce848ff84edd 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -276,9 +276,12 @@ void arch_touch_nmi_watchdog(void) { unsigned long ticks = tb_ticks_per_usec * wd_timer_period_ms * 1000; int cpu = smp_processor_id(); + u64 tb = get_tb(); - if (get_tb() - per_cpu(wd_timer_tb, cpu) >= ticks) - watchdog_timer_interrupt(cpu); + if (tb - per_cpu(wd_timer_tb, cpu) >= ticks) { + per_cpu(wd_timer_tb, cpu) = tb; + wd_smp_clear_cpu_pending(cpu, tb); + } } EXPORT_SYMBOL(arch_touch_nmi_watchdog); |