This commit introduces can_sleep and short_spin local variables to hazptr_read_delay(). The can_sleep variable records whether unconstrained sleeping is feasible, and the short_spin variable checks for the NMI handlers, IRQ handlers, or disabled interrupts/softirqs suggesting short spin times. While in the area, it disables the reader_sleep_us module parameter when invoked where sleeping is not permitted.
Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/hazptrtorture.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c index 21a72667554fe0..adaf250ecfd585 100644 --- a/kernel/rcu/hazptrtorture.c +++ b/kernel/rcu/hazptrtorture.c @@ -204,23 +204,25 @@ static struct hazptr_torture *hazptr_torture_read_lock(struct hazptr_ctx **hcpp) static void hazptr_read_delay(struct torture_random_state *rrsp) { + const bool can_sleep = !preempt_count() && !irqs_disabled(); const unsigned long shortdelay_us = 200; unsigned long longdelay_ms = 300; + const bool short_spin = irqs_disabled() || irq_count(); /* We want a short delay sometimes to make a reader delay the grace * period, and we want a long delay occasionally to trigger * force_quiescent_state. */ if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { - if ((preempt_count() & HARDIRQ_MASK) || softirq_count()) + if (short_spin) longdelay_ms = 5; /* Avoid triggering BH limits. */ mdelay(longdelay_ms); } if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) udelay(shortdelay_us); - if (!preempt_count() && !(torture_random(rrsp) % (nrealreaders * 500))) + if (can_sleep && !(torture_random(rrsp) % (nrealreaders * 500))) torture_preempt_schedule(); /* QS only if preemptible. */ - if (reader_sleep_us > 0) + if (can_sleep && reader_sleep_us > 0) torture_hrtimeout_us(reader_sleep_us, 0, NULL); } -- 2.40.1
