Re: [PATCH][2.6.10-rc2-mm4] perfctr sysfs update 1/4: core

From: Mikael Pettersson
Date: Fri Dec 03 2004 - 04:55:57 EST


Greg KH writes:
> On Thu, Dec 02, 2004 at 11:10:24AM +0100, Mikael Pettersson wrote:
> > +static int __init perfctr_class_init(void)
> > +{
> > + int ret;
> > +
> > + ret = class_register(&perfctr_class);
> > + if (ret)
> > + return ret;
> > + ret |= class_create_file(&perfctr_class, &class_attr_driver_version);
> > + ret |= class_create_file(&perfctr_class, &class_attr_cpu_type);
> > + ret |= class_create_file(&perfctr_class, &class_attr_cpu_features);
> > + ret |= class_create_file(&perfctr_class, &class_attr_cpu_khz);
> > + ret |= class_create_file(&perfctr_class, &class_attr_tsc_to_cpu_mult);
> > + ret |= class_create_file(&perfctr_class, &class_attr_cpus_online);
> > + ret |= class_create_file(&perfctr_class, &class_attr_cpus_forbidden);
> > + if (ret)
> > + class_unregister(&perfctr_class);
> > + return ret;
>
> It's easier to use sysfs_create_group() instead of registering all of
> the individual files.

Thanks for the hint. While looking around I noticed I can simplify
it even further by having perfctr_class.class_attrs point to an array
of attributes at class_register() time.

Perfctr sysfs update:
- Simplify perfctr sysfs code.

Signed-off-by: Mikael Pettersson <mikpe@xxxxxxxxx>

drivers/perfctr/init.c | 58 ++++++++++++++++++-------------------------------
1 files changed, 22 insertions(+), 36 deletions(-)

diff -rupN linux-2.6.10-rc2-mm4/drivers/perfctr/init.c linux-2.6.10-rc2-mm4.perfctr-core-update2/drivers/perfctr/init.c
--- linux-2.6.10-rc2-mm4/drivers/perfctr/init.c 2004-12-03 01:52:19.000000000 +0100
+++ linux-2.6.10-rc2-mm4.perfctr-core-update2/drivers/perfctr/init.c 2004-12-03 01:51:37.000000000 +0100
@@ -22,81 +22,67 @@ struct perfctr_info perfctr_info = {
.driver_version = VERSION,
};

-static struct class perfctr_class = {
- .name = "perfctr",
-};
-
static ssize_t
-perfctr_show_driver_version(struct class *class, char *buf)
+driver_version_show(struct class *class, char *buf)
{
return sprintf(buf, "%s\n", perfctr_info.driver_version);
}
-static CLASS_ATTR(driver_version,0444,perfctr_show_driver_version,NULL);

static ssize_t
-perfctr_show_cpu_type(struct class *class, char *buf)
+cpu_type_show(struct class *class, char *buf)
{
return sprintf(buf, "%#x\n", perfctr_info.cpu_type);
}
-static CLASS_ATTR(cpu_type,0444,perfctr_show_cpu_type,NULL);

static ssize_t
-perfctr_show_cpu_features(struct class *class, char *buf)
+cpu_features_show(struct class *class, char *buf)
{
return sprintf(buf, "%#x\n", perfctr_info.cpu_features);
}
-static CLASS_ATTR(cpu_features,0444,perfctr_show_cpu_features,NULL);

static ssize_t
-perfctr_show_cpu_khz(struct class *class, char *buf)
+cpu_khz_show(struct class *class, char *buf)
{
return sprintf(buf, "%u\n", perfctr_info.cpu_khz);
}
-static CLASS_ATTR(cpu_khz,0444,perfctr_show_cpu_khz,NULL);

static ssize_t
-perfctr_show_tsc_to_cpu_mult(struct class *class, char *buf)
+tsc_to_cpu_mult_show(struct class *class, char *buf)
{
return sprintf(buf, "%u\n", perfctr_info.tsc_to_cpu_mult);
}
-static CLASS_ATTR(tsc_to_cpu_mult,0444,perfctr_show_tsc_to_cpu_mult,NULL);

static ssize_t
-perfctr_show_cpus_online(struct class *class, char *buf)
+cpus_online_show(struct class *class, char *buf)
{
int ret = cpumask_scnprintf(buf, PAGE_SIZE-1, cpu_online_map);
buf[ret++] = '\n';
return ret;
}
-static CLASS_ATTR(cpus_online,0444,perfctr_show_cpus_online,NULL);

static ssize_t
-perfctr_show_cpus_forbidden(struct class *class, char *buf)
+cpus_forbidden_show(struct class *class, char *buf)
{
int ret = cpumask_scnprintf(buf, PAGE_SIZE-1, perfctr_cpus_forbidden_mask);
buf[ret++] = '\n';
return ret;
}
-static CLASS_ATTR(cpus_forbidden,0444,perfctr_show_cpus_forbidden,NULL);

-static int __init perfctr_class_init(void)
-{
- int ret;
+static struct class_attribute perfctr_class_attrs[] = {
+ __ATTR_RO(driver_version),
+ __ATTR_RO(cpu_type),
+ __ATTR_RO(cpu_features),
+ __ATTR_RO(cpu_khz),
+ __ATTR_RO(tsc_to_cpu_mult),
+ __ATTR_RO(cpus_online),
+ __ATTR_RO(cpus_forbidden),
+ __ATTR_NULL
+};

- ret = class_register(&perfctr_class);
- if (ret)
- return ret;
- ret |= class_create_file(&perfctr_class, &class_attr_driver_version);
- ret |= class_create_file(&perfctr_class, &class_attr_cpu_type);
- ret |= class_create_file(&perfctr_class, &class_attr_cpu_features);
- ret |= class_create_file(&perfctr_class, &class_attr_cpu_khz);
- ret |= class_create_file(&perfctr_class, &class_attr_tsc_to_cpu_mult);
- ret |= class_create_file(&perfctr_class, &class_attr_cpus_online);
- ret |= class_create_file(&perfctr_class, &class_attr_cpus_forbidden);
- if (ret)
- class_unregister(&perfctr_class);
- return ret;
-}
+static struct class perfctr_class = {
+ .name = "perfctr",
+ .class_attrs = perfctr_class_attrs,
+};

char *perfctr_cpu_name __initdata;

@@ -112,7 +98,7 @@ static int __init perfctr_init(void)
err = vperfctr_init();
if (err)
return err;
- err = perfctr_class_init();
+ err = class_register(&perfctr_class);
if (err) {
printk(KERN_ERR "perfctr: class initialisation failed\n");
return err;
-
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