preempt/dynamic: Provide cond_resched() and might_resched() static calls

mainline inclusion
from mainline-5.12-rc1
commit b965f1dd
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I410UT
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b965f1ddb47daa5b8b2e2bc9c921431236830367



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

Provide static calls to control cond_resched() (called in !CONFIG_PREEMPT)
and might_resched() (called in CONFIG_PREEMPT_VOLUNTARY) to that we
can override their behaviour when preempt= is overriden.

Since the default behaviour is full preemption, both their calls are
ignored when preempt= isn't passed.

  [fweisbec: branch might_resched() directly to __cond_resched(), only
             define static calls when PREEMPT_DYNAMIC]

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210118141223.123667-6-frederic@kernel.org


Signed-off-by: Ma Junhai <majunhai2@huawei.com>

 Conflicts:
	include/linux/kernel.h
Reviewed-by: Chen Hui <judy.chenhui@huawei.com>

Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>