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authorPaul E. McKenney <paulmck@kernel.org>2023-05-16 08:22:31 -0700
committerPaul E. McKenney <paulmck@kernel.org>2023-07-14 15:01:49 -0700
commit7221f493c5ff8bee5c39de1e43cb8a8997c2cda5 (patch)
tree858b14e07d310b3f07e4d98570c5e1086720f4a8 /kernel/rcu
parentee7516a16350ce2c1d45314a8c79bc93750fca8f (diff)
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 <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/rcuscale.c5
1 files changed, 4 insertions, 1 deletions
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",