linux-kernel - [PATCH rcu 04/17] refscale: Simplify the errexit checkpoint

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Date:   Wed,  1 Dec 2021 16:43:23 -0800
From:   "Paul E. McKenney" <paulmck@...nel.org>
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel-team@...com, mingo@...nel.org,
        jiangshanlai@...il.com, akpm@...ux-foundation.org,
        mathieu.desnoyers@...icios.com, josh@...htriplett.org,
        tglx@...utronix.de, peterz@...radead.org, rostedt@...dmis.org,
        dhowells@...hat.com, edumazet@...gle.com, fweisbec@...il.com,
        oleg@...hat.com, joel@...lfernandes.org,
        Li Zhijian <lizhijian@...fujitsu.com>,
        "Paul E . McKenney" <paulmck@...nel.org>
Subject: [PATCH rcu 04/17] refscale: Simplify the errexit checkpoint

From: Li Zhijian <lizhijian@...fujitsu.com>

There is only the one OOM error case in main_func(), so this commit
eliminates the errexit local variable in favor of a branch to cleanup
code.

Signed-off-by: Li Zhijian <lizhijian@...fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
 kernel/rcu/refscale.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 1631ef8a138db..b59457cef88d5 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -637,7 +637,6 @@ static u64 process_durations(int n)
 // point all the timestamps are printed.
 static int main_func(void *arg)
 {
-	bool errexit = false;
 	int exp, r;
 	char buf1[64];
 	char *buf;
@@ -651,7 +650,7 @@ static int main_func(void *arg)
 	buf = kzalloc(64 + nruns * 32, GFP_KERNEL);
 	if (!result_avg || !buf) {
 		VERBOSE_SCALEOUT_ERRSTRING("out of memory");
-		errexit = true;
+		goto oom_exit;
 	}
 	if (holdoff)
 		schedule_timeout_interruptible(holdoff * HZ);
@@ -663,8 +662,6 @@ static int main_func(void *arg)
 
 	// Start exp readers up per experiment
 	for (exp = 0; exp < nruns && !torture_must_stop(); exp++) {
-		if (errexit)
-			break;
 		if (torture_must_stop())
 			goto end;
 
@@ -698,26 +695,22 @@ static int main_func(void *arg)
 	// Print the average of all experiments
 	SCALEOUT("END OF TEST. Calculating average duration per loop (nanoseconds)...\n");
 
-	if (!errexit) {
-		buf[0] = 0;
-		strcat(buf, "\n");
-		strcat(buf, "Runs\tTime(ns)\n");
-	}
+	buf[0] = 0;
+	strcat(buf, "\n");
+	strcat(buf, "Runs\tTime(ns)\n");
 
 	for (exp = 0; exp < nruns; exp++) {
 		u64 avg;
 		u32 rem;
 
-		if (errexit)
-			break;
 		avg = div_u64_rem(result_avg[exp], 1000, &rem);
 		sprintf(buf1, "%d\t%llu.%03u\n", exp + 1, avg, rem);
 		strcat(buf, buf1);
 	}
 
-	if (!errexit)
-		SCALEOUT("%s", buf);
+	SCALEOUT("%s", buf);
 
+oom_exit:
 	// This will shutdown everything including us.
 	if (shutdown) {
 		shutdown_start = 1;
-- 
2.31.1.189.g2e36527f23