From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
process_durations() is not a hot path, but there is no good reason to
iterate over and over the data already in 'buf'.
Using a seq_buf saves some useless strcat() and the need of a temp buffer.
Data is written directly at the correct place.
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Tested-by: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@xxxxxxxxxx>
---
kernel/rcu/refscale.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index f4ea5b1ec068..cfec0648e141 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -28,6 +28,7 @@
#include <linux/rcupdate_trace.h>
#include <linux/reboot.h>
#include <linux/sched.h>
+#include <linux/seq_buf.h>
#include <linux/spinlock.h>
#include <linux/smp.h>
#include <linux/stat.h>
@@ -891,32 +892,34 @@ static u64 process_durations(int n)
{
int i;
struct reader_task *rt;
- char buf1[64];
+ struct seq_buf s;
char *buf;
u64 sum = 0;
buf = kmalloc(800 + 64, GFP_KERNEL);
if (!buf)
return 0;
- buf[0] = 0;
- sprintf(buf, "Experiment #%d (Format: <THREAD-NUM>:<Total loop time in ns>)",
- exp_idx);
+ seq_buf_init(&s, buf, 800 + 64);
+
+ seq_buf_printf(&s, "Experiment #%d (Format: <THREAD-NUM>:<Total loop time in ns>)",
+ exp_idx);
for (i = 0; i < n && !torture_must_stop(); i++) {
rt = &(reader_tasks[i]);
- sprintf(buf1, "%d: %llu\t", i, rt->last_duration_ns);
if (i % 5 == 0)
- strcat(buf, "\n");
- if (strlen(buf) >= 800) {
- pr_alert("%s", buf);
- buf[0] = 0;
+ seq_buf_putc(&s, '\n');
+
+ if (seq_buf_used(&s) >= 800) {
+ pr_alert("%s", seq_buf_str(&s));
+ seq_buf_clear(&s);
}
- strcat(buf, buf1);
+
+ seq_buf_printf(&s, "%d: %llu\t", i, rt->last_duration_ns);
sum += rt->last_duration_ns;
}
- pr_alert("%s\n", buf);
+ pr_alert("%s\n", seq_buf_str(&s));
kfree(buf);
return sum;
--
2.40.1
