From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>,
bristot@redhat.com, frextrite@gmail.com,
madhuparnabhowmik04@gmail.com, urezki@gmail.com,
Davidlohr Bueso <dave@stgolabs.net>,
Josh Triplett <josh@joshtriplett.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
rcu@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>
Subject: [PATCH v2 rcu-dev] rcuperf: Measure memory footprint during kfree_rcu() test
Date: Thu, 19 Dec 2019 11:22:42 -0500 [thread overview]
Message-ID: <20191219162242.128282-1-joel@joelfernandes.org> (raw)
During changes to kfree_rcu() code, we often check how much is free
memory. Instead of doing so manually, add a measurement in the test
itself. We measure 4 times during the test for available memory and
compare with the beginning.
A sample run shows something like:
Total time taken by all kfree'ers: 6369738407 ns, loops: 10000, batches: 764, memory footprint: 216MB
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
v1->v2 : Minor corrections
Cc: bristot@redhat.com
Cc: frextrite@gmail.com
Cc: madhuparnabhowmik04@gmail.com
Cc: urezki@gmail.com
kernel/rcu/rcuperf.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index da94b89cd531..91f0650914cc 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/mm.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/err.h>
@@ -611,6 +612,7 @@ kfree_perf_thread(void *arg)
long me = (long)arg;
struct kfree_obj *alloc_ptr;
u64 start_time, end_time;
+ long mem_begin, mem_during = 0;
VERBOSE_PERFOUT_STRING("kfree_perf_thread task started");
set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
@@ -626,6 +628,12 @@ kfree_perf_thread(void *arg)
}
do {
+ if (!mem_during) {
+ mem_during = mem_begin = si_mem_available();
+ } else if (loop % (kfree_loops / 4) == 0) {
+ mem_during = (mem_during + si_mem_available()) / 2;
+ }
+
for (i = 0; i < kfree_alloc_num; i++) {
alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
if (!alloc_ptr)
@@ -645,9 +653,11 @@ kfree_perf_thread(void *arg)
else
b_rcu_gp_test_finished = cur_ops->get_gp_seq();
- pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld\n",
+ pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %ldMB\n",
(unsigned long long)(end_time - start_time), kfree_loops,
- rcuperf_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started));
+ rcuperf_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
+ (mem_begin - mem_during) >> (20 - PAGE_SHIFT));
+
if (shutdown) {
smp_mb(); /* Assign before wake. */
wake_up(&shutdown_wq);
--
2.24.1.735.g03f4e72817-goog
next reply other threads:[~2019-12-19 16:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 16:22 Joel Fernandes (Google) [this message]
2019-12-19 17:14 ` [PATCH v2 rcu-dev] rcuperf: Measure memory footprint during kfree_rcu() test Paul E. McKenney
2019-12-19 17:58 ` Joel Fernandes
2019-12-19 19:34 ` Paul E. McKenney
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