[LIB] pcounter : unline too big functions

Before pushing pcounter to Linus tree, I would like to make some adjustments.

Goal is to reduce kernel text size, by unlining too big functions.

When a pcounter is bound to a statically defined per_cpu variable,
we define two small helpers functions. (No more folding function
using the fat for_each_possible_cpu(cpu) ... )

static DEFINE_PER_CPU(int, NAME##_pcounter_values);
static void NAME##_pcounter_add(struct pcounter *self, int val)
{
       __get_cpu_var(NAME##_pcounter_values) += val;
}
static int NAME##_pcounter_getval(const struct pcounter *self, int cpu)
{
       return per_cpu(NAME##_pcounter_values, cpu);
}

Fast path is therefore unchanged, while folding/alloc/free is now unlined.

This saves 228 bytes on i386

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 37 insertions, 5 deletions

diff --git a/lib/pcounter.c b/lib/pcounter.c
index 93feea5..9b56807 100644
--- a/lib/pcounter.c
+++ b/lib/pcounter.c
@@ -7,20 +7,52 @@
 #include <linux/module.h>
 #include <linux/pcounter.h>
 #include <linux/smp.h>
+#include <linux/cpumask.h>
 
-void pcounter_def_add(struct pcounter *self, int inc)
+static void pcounter_dyn_add(struct pcounter *self, int inc)
 {
 	per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
 }
 
-EXPORT_SYMBOL_GPL(pcounter_def_add);
+static int pcounter_dyn_getval(const struct pcounter *self, int cpu)
+{
+	return per_cpu_ptr(self->per_cpu_values, cpu)[0];
+}
 
-int pcounter_def_getval(const struct pcounter *self)
+int pcounter_getval(const struct pcounter *self)
 {
 	int res = 0, cpu;
+
 	for_each_possible_cpu(cpu)
-		res += per_cpu_ptr(self->per_cpu_values, cpu)[0];
+		res += self->getval(self, cpu);
+
 	return res;
 }
+EXPORT_SYMBOL_GPL(pcounter_getval);
+
+int pcounter_alloc(struct pcounter *self)
+{
+	int rc = 0;
+	if (self->add == NULL) {
+		self->per_cpu_values = alloc_percpu(int);
+		if (self->per_cpu_values != NULL) {
+			self->add    = pcounter_dyn_add;
+			self->getval = pcounter_dyn_getval;
+		} else
+			rc = 1;
+	}
+	return rc;
+}
+EXPORT_SYMBOL_GPL(pcounter_alloc);
+
+void pcounter_free(struct pcounter *self)
+{
+	if (self->per_cpu_values != NULL) {
+		free_percpu(self->per_cpu_values);
+		self->per_cpu_values = NULL;
+		self->getval = NULL;
+		self->add = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(pcounter_free);
 
-EXPORT_SYMBOL_GPL(pcounter_def_getval);