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| author | Paul E. McKenney <paulmck@kernel.org> | 2021-11-23 22:53:52 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-12-08 03:36:18 +0300 |
| commit | 613b00fbe64461f1c73e035e07c22cf3de65740b (patch) | |
| tree | 637ba4f0d889f584b22511e587d2f49b61a3933f | |
| parent | 82e310033d7c21a7a88427f14e0dad78d731a5cd (diff) | |
| download | linux-613b00fbe64461f1c73e035e07c22cf3de65740b.tar.xz | |
rcutorture: Add ability to limit callback-flood intensity
The RCU tasks flavors of RCU now need concurrent callback flooding to
test their ability to switch between single-queue mode and per-CPU queue
mode, but their lack of heavy-duty forward-progress features rules out
the use of rcutorture's current callback-flooding code. This commit
therefore provides the ability to limit the intensity of the callback
floods using a new ->cbflood_max field in the rcu_operations structure.
When this field is zero, there is no limit, otherwise, each callback-flood
kthread allocates at most ->cbflood_max callbacks.
Cc: Neeraj Upadhyay <neeraj.iitr10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | kernel/rcu/rcutorture.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 9390f867ba6c..1e8360d15920 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -348,6 +348,7 @@ struct rcu_torture_ops { void (*gp_kthread_dbg)(void); bool (*check_boost_failed)(unsigned long gp_state, int *cpup); int (*stall_dur)(void); + long cbflood_max; int irq_capable; int can_boost; int extendables; @@ -841,6 +842,7 @@ static struct rcu_torture_ops tasks_rude_ops = { .call = call_rcu_tasks_rude, .cb_barrier = rcu_barrier_tasks_rude, .gp_kthread_dbg = show_rcu_tasks_rude_gp_kthread, + .cbflood_max = 50000, .fqs = NULL, .stats = NULL, .irq_capable = 1, @@ -881,6 +883,7 @@ static struct rcu_torture_ops tasks_tracing_ops = { .call = call_rcu_tasks_trace, .cb_barrier = rcu_barrier_tasks_trace, .gp_kthread_dbg = show_rcu_tasks_trace_gp_kthread, + .cbflood_max = 50000, .fqs = NULL, .stats = NULL, .irq_capable = 1, @@ -2387,7 +2390,7 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) rfp->rcu_fwd_cb_head = rfcpn; n_launders++; n_launders_sa++; - } else { + } else if (!cur_ops->cbflood_max || cur_ops->cbflood_max > n_max_cbs) { rfcp = kmalloc(sizeof(*rfcp), GFP_KERNEL); if (WARN_ON_ONCE(!rfcp)) { schedule_timeout_interruptible(1); @@ -2397,8 +2400,11 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp) n_launders_sa = 0; rfcp->rfc_gps = 0; rfcp->rfc_rfp = rfp; + } else { + rfcp = NULL; } - cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); + if (rfcp) + cur_ops->call(&rfcp->rh, rcu_torture_fwd_cb_cr); rcu_torture_fwd_prog_cond_resched(n_launders + n_max_cbs); if (tick_nohz_full_enabled()) { local_irq_save(flags); @@ -2506,8 +2512,10 @@ static int rcu_torture_fwd_prog(void *args) pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id); if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id) rcu_torture_fwd_prog_cr(rfp); - if (!IS_ENABLED(CONFIG_TINY_RCU) || - (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id)) + if ((cur_ops->stall_dur && cur_ops->stall_dur() > 0) && + (!IS_ENABLED(CONFIG_TINY_RCU) || + (rcu_inkernel_boot_has_ended() && + torture_num_online_cpus() > rfp->rcu_fwd_id))) rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); /* Avoid slow periods, better to test when busy. */ @@ -2539,7 +2547,8 @@ static int __init rcu_torture_fwd_prog_init(void) fwd_progress = nr_cpu_ids; } if ((!cur_ops->sync && !cur_ops->call) || - !cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || cur_ops == &rcu_busted_ops) { + (!cur_ops->cbflood_max && (!cur_ops->stall_dur || cur_ops->stall_dur() <= 0)) || + cur_ops == &rcu_busted_ops) { VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test"); fwd_progress = 0; return 0; |