Peter Zijlstra 5949a68c73 time/sched_clock: Provide sched_clock_noinstr()
With the intent to provide local_clock_noinstr(), a variant of
local_clock() that's safe to be called from noinstr code (with the
assumption that any such code will already be non-preemptible),
prepare for things by providing a noinstr sched_clock_noinstr() function.

Specifically, preempt_enable_*() calls out to schedule(), which upsets
noinstr validation efforts.

As such, pull out the preempt_{dis,en}able_notrace() requirements from
the sched_clock_read() implementations by explicitly providing it in
the sched_clock() function.

This further requires said sched_clock_read() functions to be noinstr
themselves, for ARCH_WANTS_NO_INSTR users. See the next few patches.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>  # Hyper-V
Link: https://lore.kernel.org/r/20230519102715.302350330@infradead.org
2023-06-05 21:11:04 +02:00
..
2020-10-30 21:57:07 +01:00
2023-04-25 11:22:46 -07:00
2023-01-03 11:07:58 +01:00