rcuperf: Add ability to increase object allocation size

This allows us to increase memory pressure dynamically using a new
rcuperf boot command line parameter called 'rcumult'.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index a4a8d09..16dd1e6 100644 (file)
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -88,6 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
 torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
+torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
 
 static char *perf_type = "rcu";
 module_param(perf_type, charp, 0444);
@@ -635,7 +636,7 @@ kfree_perf_thread(void *arg)
                }
 
                for (i = 0; i < kfree_alloc_num; i++) {
-                       alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
+                       alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
                        if (!alloc_ptr)
                                return -ENOMEM;
 
@@ -722,6 +723,8 @@ kfree_perf_init(void)
                schedule_timeout_uninterruptible(1);
        }
 
+       pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
+
        kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
                               GFP_KERNEL);
        if (kfree_reader_tasks == NULL) {