Re: [PATCH 11/68] 0 -> NULL, for arch/parisc

[Grant Grundler]

On Fri, Jul 27, 2007 at 11:45:05AM +0200, Yoann Padioleau wrote:
> 
> When comparing a pointer, it's clearer to compare it to NULL than to 0.
...
> diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
> index 04c7e1d..16fccbe 100644
> --- a/arch/parisc/kernel/smp.c
> +++ b/arch/parisc/kernel/smp.c
> @@ -333,7 +333,7 @@ smp_call_function (void (*func) (void *i
>  
>   if (retry) {
>   spin_lock (&lock);
> - while (smp_call_function_data != 0)
> + while (smp_call_function_data != NULL)
>   barrier();
>   }
>   else {

Yoann,
Thanks!
I like comparing pointers to NULL since it makes it explicit we
are dealing with a pointer and is consistent with the assignment to NULL
later in the code.

But I'd like the later comparisons of smp_call_function_data to be
consistent with your suggestion above.
Patch below adds another "!= NULL".

thanks
grant

Signed-off-by: Grant Grundler <[EMAIL PROTECTED]>


diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 04c7e1d..c9ce659 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -333,12 +333,12 @@ smp_call_function (void (*func) (void *info), void *info, 
int retry, int wait)
 
if (retry) {
spin_lock (&lock);
-   while (smp_call_function_data != 0)
+   while (smp_call_function_data != NULL)
barrier();
}
else {
spin_lock (&lock);
-   if (smp_call_function_data) {
+   if (smp_call_function_data != NULL) {
spin_unlock (&lock);
return -EBUSY;
}
-
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[PATCH 11/68] 0 -> NULL, for arch/parisc

[Yoann Padioleau]

When comparing a pointer, it's clearer to compare it to NULL than to 0.

Here is an excerpt of the semantic patch: 

@@
expression *E;
@@

  E ==
- 0
+ NULL

@@
expression *E;
@@

  E !=
- 0
+ NULL

Signed-off-by: Yoann Padioleau <[EMAIL PROTECTED]>
Cc: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]
---

 smp.c |2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 04c7e1d..16fccbe 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -333,7 +333,7 @@ smp_call_function (void (*func) (void *i
 
if (retry) {
spin_lock (&lock);
-   while (smp_call_function_data != 0)
+   while (smp_call_function_data != NULL)
barrier();
}
else {

-
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