sched/debug: Try trigger_single_cpu_backtrace(cpu) in dump_cpu_task()

mainline inclusion
from mainline-v6.1-rc1
commit e73dfe30
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7OIXK

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e73dfe30930b75c98746152e7a2f6a8ab6067b51



--------------------------------

The trigger_all_cpu_backtrace() function attempts to send an NMI to the
target CPU, which usually provides much better stack traces than the
dump_cpu_task() function's approach of dumping that stack from some other
CPU.  So much so that most calls to dump_cpu_task() only happen after
a call to trigger_all_cpu_backtrace() has failed.  And the exception to
this rule really should attempt to use trigger_all_cpu_backtrace() first.

Therefore, move the trigger_all_cpu_backtrace() invocation into
dump_cpu_task().

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Conflicts:
	kernel/smp.c

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>