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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-05-25 15:48:38 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-06-29 12:00:44 -0700 |
| commit | 8fc28783a0c3704ea27505a25dbde8333d75380c (patch) | |
| tree | 3b3590d85405229aed811d16ba120c12beca0762 /kernel/rcu | |
| parent | 83b88c86da0e5f97faeac5a9bb19fe32f8c0394b (diff) | |
| download | lwn-8fc28783a0c3704ea27505a25dbde8333d75380c.tar.gz lwn-8fc28783a0c3704ea27505a25dbde8333d75380c.zip | |
refperf: Convert nreaders to a module parameter
This commit converts nreaders to a module parameter, with the default
of -1 specifying the old behavior of using 75% of the readers.
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/refperf.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c index e991d4820f51..020e55a9a64b 100644 --- a/kernel/rcu/refperf.c +++ b/kernel/rcu/refperf.c @@ -62,6 +62,12 @@ torture_param(int, holdoff, IS_BUILTIN(CONFIG_RCU_REF_PERF_TEST) ? 10 : 0, "Holdoff time before test start (s)"); // Number of loops per experiment, all readers execute operations concurrently. torture_param(long, loops, 10000000, "Number of loops per experiment."); +// Number of readers, with -1 defaulting to about 75% of the CPUs. +torture_param(int, nreaders, -1, "Number of readers, -1 for 75% of CPUs."); +// Number of runs. +torture_param(int, nruns, 30, "Number of experiments to run."); +// Reader delay in nanoseconds, 0 for no delay. +torture_param(int, readdelay, 0, "Read-side delay in nanoseconds."); #ifdef MODULE # define REFPERF_SHUTDOWN 0 @@ -93,7 +99,6 @@ static wait_queue_head_t main_wq; static int shutdown_start; static struct reader_task *reader_tasks; -static int nreaders; // Number of readers that are part of the current experiment. static atomic_t nreaders_exp; @@ -411,8 +416,8 @@ static void ref_perf_print_module_parms(struct ref_perf_ops *cur_ops, const char *tag) { pr_alert("%s" PERF_FLAG - "--- %s: verbose=%d shutdown=%d holdoff=%d loops=%ld\n", perf_type, tag, - verbose, shutdown, holdoff, loops); + "--- %s: verbose=%d shutdown=%d holdoff=%d loops=%ld nreaders=%d\n", perf_type, tag, + verbose, shutdown, holdoff, loops, nreaders); } static void @@ -501,8 +506,9 @@ ref_perf_init(void) schedule_timeout_uninterruptible(1); } - // Reader tasks (~75% of online CPUs). - nreaders = (num_online_cpus() >> 1) + (num_online_cpus() >> 2); + // Reader tasks (default to ~75% of online CPUs). + if (nreaders < 0) + nreaders = (num_online_cpus() >> 1) + (num_online_cpus() >> 2); reader_tasks = kcalloc(nreaders, sizeof(reader_tasks[0]), GFP_KERNEL); if (!reader_tasks) { |