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authorMichael Neuling <mikey@neuling.org>2008-02-06 01:36:12 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 10:41:00 -0800
commit06b8e878a9bc9301201cffe186eba99c4185f20a (patch)
tree857434ed559cdb001177e81283be6f0b5693a781 /include/asm-powerpc/cputime.h
parentd9afa43532adf8a31b93c4c7601fda3f423d8972 (diff)
taskstats scaled time cleanup
This moves the ability to scale cputime into generic code. This allows us to fix the issue in kernel/timer.c (noticed by Balbir) where we could only add an unscaled value to the scaled utime/stime. This adds a cputime_to_scaled function. As before, the POWERPC version does the scaling based on the last SPURR/PURR ratio calculated. The generic and s390 (only other arch to implement asm/cputime.h) versions are both NOPs. Also moves the SPURR and PURR snapshots closer. Signed-off-by: Michael Neuling <mikey@neuling.org> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-powerpc/cputime.h')
-rw-r--r--include/asm-powerpc/cputime.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/asm-powerpc/cputime.h b/include/asm-powerpc/cputime.h
index 310804485208..f42e623030ee 100644
--- a/include/asm-powerpc/cputime.h
+++ b/include/asm-powerpc/cputime.h
@@ -52,12 +52,26 @@ typedef u64 cputime64_t;
* Convert cputime <-> jiffies
*/
extern u64 __cputime_jiffies_factor;
+DECLARE_PER_CPU(unsigned long, cputime_last_delta);
+DECLARE_PER_CPU(unsigned long, cputime_scaled_last_delta);
static inline unsigned long cputime_to_jiffies(const cputime_t ct)
{
return mulhdu(ct, __cputime_jiffies_factor);
}
+/* Estimate the scaled cputime by scaling the real cputime based on
+ * the last scaled to real ratio */
+static inline cputime_t cputime_to_scaled(const cputime_t ct)
+{
+ if (cpu_has_feature(CPU_FTR_SPURR) &&
+ per_cpu(cputime_last_delta, smp_processor_id()))
+ return ct *
+ per_cpu(cputime_scaled_last_delta, smp_processor_id())/
+ per_cpu(cputime_last_delta, smp_processor_id());
+ return ct;
+}
+
static inline cputime_t jiffies_to_cputime(const unsigned long jif)
{
cputime_t ct;