[PATCH 0/3] kernel-sched: Fine-tuning for eight function implementations

[PATCH 0/3] kernel-sched: Fine-tuning for eight function implementations

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 6 May 2017 21:35:45 +0200

A few update suggestions were taken into account
from static source code analysis.

Markus Elfring (3):
  Use seq_putc() in three functions
  Adjust four checks for null pointers
  Combine two seq_printf() calls into one in show_schedstat()

 kernel/sched/cpuacct.c |  6 +++---
 kernel/sched/debug.c   | 11 +++++------
 kernel/sched/stats.c   | 14 +++++---------
 3 files changed, 13 insertions(+), 18 deletions(-)

-- 
2.12.2

[PATCH 1/3] kernel-sched: Use seq_putc() in three functions

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 6 May 2017 20:45:35 +0200

Four single characters (line breaks) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 kernel/sched/cpuacct.c | 6 +++---
 kernel/sched/debug.c   | 3 +--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index f95ab29a45d0..28d9fe0df92a 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -221,7 +221,7 @@ static int __cpuacct_percpu_seq_show(struct seq_file *m,
 		percpu = cpuacct_cpuusage_read(ca, i, index);
 		seq_printf(m, "%llu ", (unsigned long long) percpu);
 	}
-	seq_printf(m, "\n");
+	seq_putc(m, '\n');
 	return 0;
 }
 
@@ -249,7 +249,7 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
 	seq_puts(m, "cpu");
 	for (index = 0; index < CPUACCT_STAT_NSTATS; index++)
 		seq_printf(m, " %s", cpuacct_stat_desc[index]);
-	seq_puts(m, "\n");
+	seq_putc(m, '\n');
 
 	for_each_possible_cpu(cpu) {
 		struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
@@ -271,7 +271,7 @@ static int cpuacct_all_seq_show(struct seq_file *m, void *V)
 			raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
 #endif
 		}
-		seq_puts(m, "\n");
+		seq_putc(m, '\n');
 	}
 	return 0;
 }
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 38f019324f1a..ff599b7f10b6 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -78,8 +78,7 @@ static int sched_feat_show(struct seq_file *m, void *v)
 			seq_puts(m, "NO_");
 		seq_printf(m, "%s ", sched_feat_names[i]);
 	}
-	seq_puts(m, "\n");
-
+	seq_putc(m, '\n');
 	return 0;
 }
 
-- 
2.12.2

[PATCH 2/3] kernel-sched: Adjust four checks for null pointers

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 6 May 2017 21:17:36 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written !…

Thus fix the affected source code place.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 kernel/sched/debug.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index ff599b7f10b6..4a1abb61d1f7 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -231,7 +231,7 @@ static void sd_free_ctl_entry(struct ctl_table **tablep)
 	for (entry = *tablep; entry->mode; entry++) {
 		if (entry->child)
 			sd_free_ctl_entry(&entry->child);
-		if (entry->proc_handler == NULL)
+		if (!entry->proc_handler)
 			kfree(entry->procname);
 	}
 
@@ -265,7 +265,7 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
 {
 	struct ctl_table *table = sd_alloc_ctl_entry(14);
 
-	if (table == NULL)
+	if (!table)
 		return NULL;
 
 	set_table_entry(&table[0], "min_interval", &sd->min_interval,
@@ -311,7 +311,7 @@ static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
 	for_each_domain(cpu, sd)
 		domain_num++;
 	entry = table = sd_alloc_ctl_entry(domain_num + 1);
-	if (table == NULL)
+	if (!table)
 		return NULL;
 
 	i = 0;
@@ -336,7 +336,7 @@ void register_sched_domain_sysctl(void)
 	WARN_ON(sd_ctl_dir[0].child);
 	sd_ctl_dir[0].child = entry;
 
-	if (entry == NULL)
+	if (!entry)
 		return;
 
 	for_each_possible_cpu(i) {
-- 
2.12.2

[PATCH 3/3] kernel-sched: Combine two seq_printf() calls into one in show_schedstat()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 6 May 2017 21:26:19 +0200

Some data were put into a sequence by two separate function calls.
Print the same data by a single function call instead.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 kernel/sched/stats.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 87e2c9f0c33e..05ee4b6dcfca 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -30,15 +30,11 @@ static int show_schedstat(struct seq_file *seq, void *v)
 
 		/* runqueue-specific stats */
 		seq_printf(seq,
-		    "cpu%d %u 0 %u %u %u %u %llu %llu %lu",
-		    cpu, rq->yld_count,
-		    rq->sched_count, rq->sched_goidle,
-		    rq->ttwu_count, rq->ttwu_local,
-		    rq->rq_cpu_time,
-		    rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
-
-		seq_printf(seq, "\n");
-
+			   "cpu%d %u 0 %u %u %u %u %llu %llu %lu\n",
+			   cpu, rq->yld_count, rq->sched_count,
+			   rq->sched_goidle, rq->ttwu_count, rq->ttwu_local,
+			   rq->rq_cpu_time, rq->rq_sched_info.run_delay,
+			   rq->rq_sched_info.pcount);
 #ifdef CONFIG_SMP
 		/* domain-specific stats */
 		rcu_read_lock();
-- 
2.12.2