The following commit has been merged into the core/rcu branch of tip: Commit-ID: 8fc28783a0c3704ea27505a25dbde8333d75380c Gitweb: https://git.kernel.org/tip/8fc28783a0c3704ea27505a25dbde8333d75380c Author: Paul E. McKenney <paulmck@xxxxxxxxxx> AuthorDate: Mon, 25 May 2020 15:48:38 -07:00 Committer: Paul E. McKenney <paulmck@xxxxxxxxxx> CommitterDate: Mon, 29 Jun 2020 12:00:44 -07:00 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@xxxxxxxxxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/refperf.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/kernel/rcu/refperf.c b/kernel/rcu/refperf.c index e991d48..020e55a 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) {
![]() |