From 7221f493c5ff8bee5c39de1e43cb8a8997c2cda5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 16 May 2023 08:22:31 -0700 Subject: rcuscale: Add minruntime module parameter By default, rcuscale collects only 100 points of data per writer, but arranging for all kthreads to be actively collecting (if not recording) data during the time that any kthread might be recording. This works well, but does not allow much time to bring external performance tools to bear. This commit therefore adds a minruntime module parameter that specifies a minimum data-collection interval in seconds. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcuscale.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/rcu/rcuscale.c') diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 15edd8c82933..7c5bab5a4f19 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -87,6 +87,7 @@ torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives"); torture_param(int, gp_async_max, 1000, "Max # outstanding waits per writer"); torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); torture_param(int, holdoff, 10, "Holdoff time before test start (s)"); +torture_param(int, minruntime, 0, "Minimum run time (s)"); torture_param(int, nreaders, -1, "Number of RCU reader threads"); torture_param(int, nwriters, -1, "Number of RCU updater threads"); torture_param(bool, shutdown, RCUSCALE_SHUTDOWN, @@ -411,6 +412,7 @@ rcu_scale_writer(void *arg) { int i = 0; int i_max; + unsigned long jdone; long me = (long)arg; struct rcu_head *rhp = NULL; bool started = false, done = false, alldone = false; @@ -447,6 +449,7 @@ rcu_scale_writer(void *arg) } } + jdone = jiffies + minruntime * HZ; do { if (writer_holdoff) udelay(writer_holdoff); @@ -479,7 +482,7 @@ retry: if (!started && atomic_read(&n_rcu_scale_writer_started) >= nrealwriters) started = true; - if (!done && i >= MIN_MEAS) { + if (!done && i >= MIN_MEAS && time_after(jiffies, jdone)) { done = true; sched_set_normal(current, 0); pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n", -- cgit v1.2.3