File powerpc-utils-fix_integer_to_float_cast.patch of Package powerpc-utils

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File powerpc-utils-fix_integer_to_float_cast.patch of Package powerpc-utils (Revision 556ca36db8c068cd9daea40293bb3d0b)

Currently displaying revision 556ca36db8c068cd9daea40293bb3d0b , Show latest

commit c61535c62111d04a886a2b4d7613b7006d5fe209
Author: John Allen <jallen@linux.vnet.ibm.com>
Date:   Thu Aug 11 16:30:12 2016 -0400

lparstat: Fix bad cast from integer to float
    
    Fix a bug where the cpu stats (%user, %sys, %wait, and %idle) do not add
    up to 100%. The problem was that we were casting the cpu stats and the
    total cpu time to floats from ints. For large integer values, this would
    cause the floating point representation to be truncated. This solution
    avoids the casts and stores the cpu stats as long longs and only casts
    'total' to a long double in order to perform floating point division.
    
    Additionally, this patch parses the proc stat values as long longs as
    on systems that have been running for a long time, these values can exceed
    the maximum 32 bit integer limit.
    
    Signed-off-by: John Allen <jallen@linux.vnet.ibm.com>

diff --git a/src/lparstat.c b/src/lparstat.c
index ebe0d13..bd4ff58 100644
--- a/src/lparstat.c
+++ b/src/lparstat.c
@@ -264,11 +264,11 @@ int parse_proc_stat()
 	statvals[0] = 0;
 	value = line;
 	for (i = 1; i <= (entries - 1); i++) {
-		int v;
+		long long v;
 		value = strchr(value, ' ') + 1;
 		if (i == 1)
 			value++;
-		v = atoi(value);
+		v = atoll(value);
 		statvals[i] = v;
 		statvals[0] += v;
 	}
@@ -465,13 +465,13 @@ long long get_cpu_time_diff()
 
 void get_cpu_stat(struct sysentry *se, char *buf)
 {
-	float total, percent;
-	float old_val, new_val;
+	float percent;
+	long long total, old_val, new_val;
 
 	total = get_cpu_time_diff();
-	new_val = atoi(se->value);
-	old_val = atoi(se->old_value);
-	percent = (float)((new_val - old_val)/total) * 100;
+	new_val = atoll(se->value);
+	old_val = atoll(se->old_value);
+	percent = ((new_val - old_val)/(long double)total) * 100;
 	sprintf(buf, "%.2f", percent);
 }

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File powerpc-utils-fix_integer_to_float_cast.patch of Package powerpc-utils (Revision 556ca36db8c068cd9daea40293bb3d0b)

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