Hi Andrew,

Pekka Enberg <[EMAIL PROTECTED]> wrote:
> > This patch converts kernel/ to use kcalloc instead of kmalloc/memset.

On Thu, 4 Aug 2005, Andrew Morton wrote:
> grr.

I am learning grep. Please don't eat me!

> >  -  struct resource *res = kmalloc(sizeof(*res), GFP_KERNEL);
> >  +  struct resource *res = kcalloc(1, sizeof(*res), GFP_KERNEL);
> 
> Notice how every conversion you did passes in `1' in the first argument?
> 
> And that's going to happen again and again and again.  Each callsite
> needlessly passing that silly third argument, adding more kernel text.
> 
> If we're going to do this, we should add a two-arg helper function first,
> and use that, no?

This was discussed some time ago [1] and here's a patch for you to do 
that.

                Pekka

  1. http://marc.theaimsgroup.com/?l=linux-kernel&m=111279001428661&w=2

[PATCH] use kzalloc instead of kmalloc/memset

This patch introduces a kzalloc wrapper and converts kernel/ to use it.

Signed-off-by: Pekka Enberg <[EMAIL PROTECTED]>
---

 include/linux/slab.h |    5 +++++
 kernel/intermodule.c |    3 +--
 kernel/params.c      |    4 ++--
 kernel/power/pm.c    |    3 +--
 kernel/resource.c    |    3 +--
 kernel/workqueue.c   |    3 +--
 6 files changed, 11 insertions(+), 10 deletions(-)

Index: 2.6/kernel/resource.c
===================================================================
--- 2.6.orig/kernel/resource.c
+++ 2.6/kernel/resource.c
@@ -430,10 +430,9 @@ EXPORT_SYMBOL(adjust_resource);
  */
 struct resource * __request_region(struct resource *parent, unsigned long 
start, unsigned long n, const char *name)
 {
-       struct resource *res = kmalloc(sizeof(*res), GFP_KERNEL);
+       struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL);
 
        if (res) {
-               memset(res, 0, sizeof(*res));
                res->name = name;
                res->start = start;
                res->end = start + n - 1;
Index: 2.6/kernel/intermodule.c
===================================================================
--- 2.6.orig/kernel/intermodule.c
+++ 2.6/kernel/intermodule.c
@@ -39,7 +39,7 @@ void inter_module_register(const char *i
        struct list_head *tmp;
        struct inter_module_entry *ime, *ime_new;
 
-       if (!(ime_new = kmalloc(sizeof(*ime), GFP_KERNEL))) {
+       if (!(ime_new = kzalloc(sizeof(*ime), GFP_KERNEL))) {
                /* Overloaded kernel, not fatal */
                printk(KERN_ERR
                        "Aiee, inter_module_register: cannot kmalloc entry for 
'%s'\n",
@@ -47,7 +47,6 @@ void inter_module_register(const char *i
                kmalloc_failed = 1;
                return;
        }
-       memset(ime_new, 0, sizeof(*ime_new));
        ime_new->im_name = im_name;
        ime_new->owner = owner;
        ime_new->userdata = userdata;
Index: 2.6/kernel/params.c
===================================================================
--- 2.6.orig/kernel/params.c
+++ 2.6/kernel/params.c
@@ -542,8 +542,8 @@ static void __init kernel_param_sysfs_se
 {
        struct module_kobject *mk;
 
-       mk = kmalloc(sizeof(struct module_kobject), GFP_KERNEL);
-       memset(mk, 0, sizeof(struct module_kobject));
+       mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
+       BUG_ON(!mk);
 
        mk->mod = THIS_MODULE;
        kobj_set_kset_s(mk, module_subsys);
Index: 2.6/kernel/power/pm.c
===================================================================
--- 2.6.orig/kernel/power/pm.c
+++ 2.6/kernel/power/pm.c
@@ -60,9 +60,8 @@ struct pm_dev *pm_register(pm_dev_t type
                           unsigned long id,
                           pm_callback callback)
 {
-       struct pm_dev *dev = kmalloc(sizeof(struct pm_dev), GFP_KERNEL);
+       struct pm_dev *dev = kzalloc(sizeof(struct pm_dev), GFP_KERNEL);
        if (dev) {
-               memset(dev, 0, sizeof(*dev));
                dev->type = type;
                dev->id = id;
                dev->callback = callback;
Index: 2.6/kernel/workqueue.c
===================================================================
--- 2.6.orig/kernel/workqueue.c
+++ 2.6/kernel/workqueue.c
@@ -310,10 +310,9 @@ struct workqueue_struct *__create_workqu
 
        BUG_ON(strlen(name) > 10);
 
-       wq = kmalloc(sizeof(*wq), GFP_KERNEL);
+       wq = kzalloc(sizeof(*wq), GFP_KERNEL);
        if (!wq)
                return NULL;
-       memset(wq, 0, sizeof(*wq));
 
        wq->name = name;
        /* We don't need the distraction of CPUs appearing and vanishing. */
Index: 2.6/include/linux/slab.h
===================================================================
--- 2.6.orig/include/linux/slab.h
+++ 2.6/include/linux/slab.h
@@ -103,6 +103,11 @@ extern void *kcalloc(size_t, size_t, uns
 extern void kfree(const void *);
 extern unsigned int ksize(const void *);
 
+static inline void *kzalloc(size_t size, unsigned int __nocast flags)
+{
+       return kcalloc(1, size, flags);
+}
+
 #ifdef CONFIG_NUMA
 extern void *kmem_cache_alloc_node(kmem_cache_t *, int flags, int node);
 extern void *kmalloc_node(size_t size, unsigned int __nocast flags, int node);
-
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