Re: /proc or ps tools bug? 2.6.3, time is off

[Tim Schmielau]

> diff -Nru a/include/linux/times.h b/include/linux/times.h
> --- a/include/linux/times.h	Tue Apr 13 15:00:25 2004
> +++ b/include/linux/times.h	Tue Apr 13 15:00:25 2004
> @@ -7,7 +7,12 @@
>  #include <asm/param.h>
>  
>  #if (HZ % USER_HZ)==0
> -# define jiffies_to_clock_t(x) ((x) / (HZ / USER_HZ))
> +static inline long jiffies_to_clock_t(long x)
> +{
> +	u64 tmp = (u64)x * TICK_NSEC;
> +	x = do_div(tmp, (NSEC_PER_SEC / USER_HZ));
> +	return (long)tmp;
> +}
>  #else
>  # define jiffies_to_clock_t(x) ((clock_t) jiffies_64_to_clock_t((u64) x))
>  #endif

Excuse me for barging in lately and innocently, but I find this patch
hard to comprehend:
 - shouldn't a foo_to_clock_t() function return a clock?
 - the x = seems superfluous
 - the #if is not a shortcut anymore, so why keep it?
Shouldn't this patch be more like the following
(completely untested)?

Tim


diff -urp --exclude-from dontdiff linux-2.6.5/include/linux/times.h linux-2.6.5-jfix1/include/linux/times.h
--- linux-2.6.5/include/linux/times.h	2004-02-04 04:43:09.000000000 +0100
+++ linux-2.6.5-jfix1/include/linux/times.h	2004-04-14 13:48:57.000000000 +0200
@@ -6,11 +6,16 @@
 #include <asm/types.h>
 #include <asm/param.h>
 
-#if (HZ % USER_HZ)==0
-# define jiffies_to_clock_t(x) ((x) / (HZ / USER_HZ))
-#else
-# define jiffies_to_clock_t(x) ((clock_t) jiffies_64_to_clock_t((u64) x))
-#endif
+static inline clock_t jiffies_to_clock_t(long x)
+{
+#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
+	return x / (HZ / USER_HZ);
+#else
+	u64 tmp = (u64)x * TICK_NSEC;
+	do_div(tmp, (NSEC_PER_SEC / USER_HZ));
+	return (long)tmp;
+#endif
+}
 
 static inline unsigned long clock_t_to_jiffies(unsigned long x)
 {
-
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