[PATCH] kernel: time: use ARRAY_SIZE macro in timecompare.c

[PATCH] kernel: time: use ARRAY_SIZE macro in timecompare.c

[Nikitas Angelinas]

Replace sizeof(buffer)/sizeof(buffer[0]) with ARRAY_SIZE(buffer) in
kernel/time/timecompare.c

Signed-off-by: Nikitas Angelinas <nikitasangelinas@googlemail.com>
---
 kernel/time/timecompare.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
index ac38fbb..a9ae369 100644
--- a/kernel/time/timecompare.c
+++ b/kernel/time/timecompare.c
@@ -21,6 +21,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/math64.h>
+#include <linux/kernel.h>
 
 /*
  * fixed point arithmetic scale factor for skew
@@ -57,11 +58,11 @@ int timecompare_offset(struct timecompare *sync,
 	int index;
 	int num_samples = sync->num_samples;
 
-	if (num_samples > sizeof(buffer)/sizeof(buffer[0])) {
+	if (num_samples > ARRAY_SIZE(buffer)) {
 		samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC);
 		if (!samples) {
 			samples = buffer;
-			num_samples = sizeof(buffer)/sizeof(buffer[0]);
+			num_samples = ARRAY_SIZE(buffer);
 		}
 	} else {
 		samples = buffer;
-- 
1.7.1.1

Re: [PATCH] kernel: time: use ARRAY_SIZE macro in timecompare.c

[Dmitry Torokhov]

On Aug 22, 2010, at 4:43 PM, Nikitas Angelinas <nikitasangelinas@googlemail.com 
 > wrote:

> Replace sizeof(buffer)/sizeof(buffer[0]) with ARRAY_SIZE(buffer) in
> kernel/time/timecompare.c
>
> Signed-off-by: Nikitas Angelinas <nikitasangelinas@googlemail.com>
> ---
> kernel/time/timecompare.c |    5 +++--
> 1 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
> index ac38fbb..a9ae369 100644
> --- a/kernel/time/timecompare.c
> +++ b/kernel/time/timecompare.c
> @@ -21,6 +21,7 @@
> #include <linux/module.h>
> #include <linux/slab.h>
> #include <linux/math64.h>
> +#include <linux/kernel.h>
>
> /*
>  * fixed point arithmetic scale factor for skew
> @@ -57,11 +58,11 @@ int timecompare_offset(struct timecompare *sync,
>    int index;
>    int num_samples = sync->num_samples;
>
> -    if (num_samples > sizeof(buffer)/sizeof(buffer[0])) {
> +    if (num_samples > ARRAY_SIZE(buffer)) {
>        samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC);

That should be kcalloc while you are at it.

Thanks.

-- 
Dmitry

Re: [PATCH] kernel: time: use ARRAY_SIZE macro in timecompare.c

[Nikitas Angelinas]

On Sun, 22 Aug 2010, Dmitry Torokhov wrote:

> On Aug 22, 2010, at 4:43 PM, Nikitas Angelinas
> <nikitasangelinas@googlemail.com> wrote:
> 
> >Replace sizeof(buffer)/sizeof(buffer[0]) with ARRAY_SIZE(buffer) in
> >kernel/time/timecompare.c
> >
> >Signed-off-by: Nikitas Angelinas <nikitasangelinas@googlemail.com>
> >---
> >kernel/time/timecompare.c |    5 +++--
> >1 files changed, 3 insertions(+), 2 deletions(-)
> >
> >diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
> >index ac38fbb..a9ae369 100644
> >--- a/kernel/time/timecompare.c
> >+++ b/kernel/time/timecompare.c
> >@@ -21,6 +21,7 @@
> >#include <linux/module.h>
> >#include <linux/slab.h>
> >#include <linux/math64.h>
> >+#include <linux/kernel.h>
> >
> >/*
> >* fixed point arithmetic scale factor for skew
> >@@ -57,11 +58,11 @@ int timecompare_offset(struct timecompare *sync,
> >   int index;
> >   int num_samples = sync->num_samples;
> >
> >-    if (num_samples > sizeof(buffer)/sizeof(buffer[0])) {
> >+    if (num_samples > ARRAY_SIZE(buffer)) {
> >       samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC);
> 
> That should be kcalloc while you are at it.
> 
> Thanks.
> 
> -- 
> Dmitry
> 
> 

Thanks for pointing that out; however, the code as is does not do a
memset to 0; is it worth using kcalloc in this case considering it has
to go through an 'unlikely' and a subsequent memset?

If required, I guess I should post a patch on a separate thread so that
Git picks up the correct patch title?

Kind Regards,
Nikitas

Re: [PATCH] kernel: time: use ARRAY_SIZE macro in timecompare.c

[Dmitry Torokhov]

On Tue, Aug 24, 2010 at 12:27:08AM +0100, Nikitas Angelinas wrote:
> 
> 
> On Sun, 22 Aug 2010, Dmitry Torokhov wrote:
> 
> > On Aug 22, 2010, at 4:43 PM, Nikitas Angelinas
> > <nikitasangelinas@googlemail.com> wrote:
> > 
> > >Replace sizeof(buffer)/sizeof(buffer[0]) with ARRAY_SIZE(buffer) in
> > >kernel/time/timecompare.c
> > >
> > >Signed-off-by: Nikitas Angelinas <nikitasangelinas@googlemail.com>
> > >---
> > >kernel/time/timecompare.c |    5 +++--
> > >1 files changed, 3 insertions(+), 2 deletions(-)
> > >
> > >diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
> > >index ac38fbb..a9ae369 100644
> > >--- a/kernel/time/timecompare.c
> > >+++ b/kernel/time/timecompare.c
> > >@@ -21,6 +21,7 @@
> > >#include <linux/module.h>
> > >#include <linux/slab.h>
> > >#include <linux/math64.h>
> > >+#include <linux/kernel.h>
> > >
> > >/*
> > >* fixed point arithmetic scale factor for skew
> > >@@ -57,11 +58,11 @@ int timecompare_offset(struct timecompare *sync,
> > >   int index;
> > >   int num_samples = sync->num_samples;
> > >
> > >-    if (num_samples > sizeof(buffer)/sizeof(buffer[0])) {
> > >+    if (num_samples > ARRAY_SIZE(buffer)) {
> > >       samples = kmalloc(sizeof(*samples) * num_samples, GFP_ATOMIC);
> > 
> > That should be kcalloc while you are at it.
> > 
> > Thanks.
> > 
> > -- 
> > Dmitry
> > 
> > 
> 
> Thanks for pointing that out; however, the code as is does not do a
> memset to 0; is it worth using kcalloc in this case considering it has
> to go through an 'unlikely' and a subsequent memset?
> 

Ah, I see. Ignore me then.

Thanks.

-- 
Dmitry