diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2019-11-28 18:54:06 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-02-20 16:03:30 -0800 |
| commit | 59ee0326ccf712f9a637d5df2465a16a784cbfb0 (patch) | |
| tree | d8a1eddcf6d496bec0d6932f86081635d08b07da /kernel/rcu | |
| parent | bb6d3fb354c5ee8d6bde2d576eb7220ea09862b9 (diff) | |
rcutorture: Suppress forward-progress complaints during early boot
Some larger systems can take in excess of 50 seconds to complete their
early boot initcalls prior to spawing init. This does not in any way
help the forward-progress judgments of built-in rcutorture (when
rcutorture is built as a module, the insmod or modprobe command normally
cannot happen until some time after boot completes). This commit
therefore suppresses such complaints until about the time that init
is spawned.
This also includes a fix to a stupid error located by kbuild test robot.
[ paulmck: Apply kbuild test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ paulmck: Fix to nohz_full slow-expediting recovery logic, per bpetkov. ]
[ paulmck: Restrict splat to CONFIG_PREEMPT_RT=y kernels and simplify. ]
Tested-by: Borislav Petkov <bp@alien8.de>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 3 | ||||
| -rw-r--r-- | kernel/rcu/tree_exp.h | 7 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 12 |
3 files changed, 20 insertions, 2 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 1aeecc165b21..9ba49788cb48 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1067,7 +1067,8 @@ rcu_torture_writer(void *arg) if (stutter_wait("rcu_torture_writer") && !READ_ONCE(rcu_fwd_cb_nodelay) && !cur_ops->slow_gps && - !torture_must_stop()) + !torture_must_stop() && + rcu_inkernel_boot_has_ended()) for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) if (list_empty(&rcu_tortures[i].rtort_free) && rcu_access_pointer(rcu_torture_current) != diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index dcbd75791f39..a72d16eb869e 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -485,6 +485,7 @@ static bool synchronize_rcu_expedited_wait_once(long tlimit) static void synchronize_rcu_expedited_wait(void) { int cpu; + unsigned long j; unsigned long jiffies_stall; unsigned long jiffies_start; unsigned long mask; @@ -496,7 +497,7 @@ static void synchronize_rcu_expedited_wait(void) trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("startwait")); jiffies_stall = rcu_jiffies_till_stall_check(); jiffies_start = jiffies; - if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { + if (tick_nohz_full_enabled() && rcu_inkernel_boot_has_ended()) { if (synchronize_rcu_expedited_wait_once(1)) return; rcu_for_each_leaf_node(rnp) { @@ -508,6 +509,10 @@ static void synchronize_rcu_expedited_wait(void) tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP); } } + j = READ_ONCE(jiffies_till_first_fqs); + if (synchronize_rcu_expedited_wait_once(j + HZ)) + return; + WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_RT)); } for (;;) { diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 6c4b862f57d6..feaaec5747a3 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -183,6 +183,8 @@ void rcu_unexpedite_gp(void) } EXPORT_SYMBOL_GPL(rcu_unexpedite_gp); +static bool rcu_boot_ended __read_mostly; + /* * Inform RCU of the end of the in-kernel boot sequence. */ @@ -191,7 +193,17 @@ void rcu_end_inkernel_boot(void) rcu_unexpedite_gp(); if (rcu_normal_after_boot) WRITE_ONCE(rcu_normal, 1); + rcu_boot_ended = 1; +} + +/* + * Let rcutorture know when it is OK to turn it up to eleven. + */ +bool rcu_inkernel_boot_has_ended(void) +{ + return rcu_boot_ended; } +EXPORT_SYMBOL_GPL(rcu_inkernel_boot_has_ended); #endif /* #ifndef CONFIG_TINY_RCU */ |