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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-11-15 21:24:52 +0300 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-01-07 04:08:09 +0300 |
| commit | e76506f0e85129d726c487c873a2245c92446515 (patch) | |
| tree | d0faf8f967b063a9b29e7f66b65f5118b20118be /kernel/rcu | |
| parent | f3ea978b712f768a02137e867aced5bfdcea670e (diff) | |
| download | linux-e76506f0e85129d726c487c873a2245c92446515.tar.xz | |
refscale: Allow summarization of verbose output
The refscale test prints enough per-kthread console output to provoke RCU
CPU stall warnings on large systems. This commit therefore allows this
output to be summarized. For example, the refscale.verbose_batched=32
boot parameter would causes only every 32nd line of output to be logged.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/refscale.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index 23ff36a66f97..3da246f2ccf5 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -46,6 +46,16 @@ #define VERBOSE_SCALEOUT(s, x...) \ do { if (verbose) pr_alert("%s" SCALE_FLAG s, scale_type, ## x); } while (0) +static atomic_t verbose_batch_ctr; + +#define VERBOSE_SCALEOUT_BATCH(s, x...) \ +do { \ + if (verbose && \ + (verbose_batched <= 0 || \ + !(atomic_inc_return(&verbose_batch_ctr) % verbose_batched))) \ + pr_alert("%s" SCALE_FLAG s, scale_type, ## x); \ +} while (0) + #define VERBOSE_SCALEOUT_ERRSTRING(s, x...) \ do { if (verbose) pr_alert("%s" SCALE_FLAG "!!! " s, scale_type, ## x); } while (0) @@ -57,6 +67,7 @@ module_param(scale_type, charp, 0444); MODULE_PARM_DESC(scale_type, "Type of test (rcu, srcu, refcnt, rwsem, rwlock."); torture_param(int, verbose, 0, "Enable verbose debugging printk()s"); +torture_param(int, verbose_batched, 0, "Batch verbose debugging printk()s"); // Wait until there are multiple CPUs before starting test. torture_param(int, holdoff, IS_BUILTIN(CONFIG_RCU_REF_SCALE_TEST) ? 10 : 0, @@ -368,14 +379,14 @@ ref_scale_reader(void *arg) u64 start; s64 duration; - VERBOSE_SCALEOUT("ref_scale_reader %ld: task started", me); + VERBOSE_SCALEOUT_BATCH("ref_scale_reader %ld: task started", me); set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids)); set_user_nice(current, MAX_NICE); atomic_inc(&n_init); if (holdoff) schedule_timeout_interruptible(holdoff * HZ); repeat: - VERBOSE_SCALEOUT("ref_scale_reader %ld: waiting to start next experiment on cpu %d", me, smp_processor_id()); + VERBOSE_SCALEOUT_BATCH("ref_scale_reader %ld: waiting to start next experiment on cpu %d", me, smp_processor_id()); // Wait for signal that this reader can start. wait_event(rt->wq, (atomic_read(&nreaders_exp) && smp_load_acquire(&rt->start_reader)) || @@ -392,7 +403,7 @@ repeat: while (atomic_read_acquire(&n_started)) cpu_relax(); - VERBOSE_SCALEOUT("ref_scale_reader %ld: experiment %d started", me, exp_idx); + VERBOSE_SCALEOUT_BATCH("ref_scale_reader %ld: experiment %d started", me, exp_idx); // To reduce noise, do an initial cache-warming invocation, check @@ -421,8 +432,8 @@ repeat: if (atomic_dec_and_test(&nreaders_exp)) wake_up(&main_wq); - VERBOSE_SCALEOUT("ref_scale_reader %ld: experiment %d ended, (readers remaining=%d)", - me, exp_idx, atomic_read(&nreaders_exp)); + VERBOSE_SCALEOUT_BATCH("ref_scale_reader %ld: experiment %d ended, (readers remaining=%d)", + me, exp_idx, atomic_read(&nreaders_exp)); if (!torture_must_stop()) goto repeat; |