taskstats: use real microsecond granularity for CPU times
The taskstats interface uses microsecond granularity for the user and
system time values. The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds. Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values. Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h
index 8b1a52a..40e2ab0 100644
--- a/arch/s390/include/asm/cputime.h
+++ b/arch/s390/include/asm/cputime.h
@@ -73,18 +73,18 @@
}
/*
- * Convert cputime to milliseconds and back.
+ * Convert cputime to microseconds and back.
*/
static inline unsigned int
-cputime_to_msecs(const cputime_t cputime)
+cputime_to_usecs(const cputime_t cputime)
{
- return cputime_div(cputime, 4096000);
+ return cputime_div(cputime, 4096);
}
static inline cputime_t
-msecs_to_cputime(const unsigned int m)
+usecs_to_cputime(const unsigned int m)
{
- return (cputime_t) m * 4096000;
+ return (cputime_t) m * 4096;
}
/*