diff options
| author | Stanislaw Gruszka <sgruszka@redhat.com> | 2009-07-29 12:15:29 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-08-03 14:48:36 +0200 |
| commit | a42548a18866e87092db93b771e6c5b060d78401 (patch) | |
| tree | 897acf5794920ec9c6fd7f87af63908d0c1988f9 /arch/powerpc/include | |
| parent | d1e3b6d195770bd422e3229b88edfc154b6a27dd (diff) | |
cputime: Optimize jiffies_to_cputime(1)
For powerpc with CONFIG_VIRT_CPU_ACCOUNTING
jiffies_to_cputime(1) is not compile time constant and run time
calculations are quite expensive. To optimize we use
precomputed value. For all other architectures is is
preprocessor definition.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/cputime.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h index f42e623030e..fa19f3fe05f 100644 --- a/arch/powerpc/include/asm/cputime.h +++ b/arch/powerpc/include/asm/cputime.h @@ -18,6 +18,9 @@ #ifndef CONFIG_VIRT_CPU_ACCOUNTING #include <asm-generic/cputime.h> +#ifdef __KERNEL__ +static inline void setup_cputime_one_jiffy(void) { } +#endif #else #include <linux/types.h> @@ -49,6 +52,11 @@ typedef u64 cputime64_t; #ifdef __KERNEL__ /* + * One jiffy in timebase units computed during initialization + */ +extern cputime_t cputime_one_jiffy; + +/* * Convert cputime <-> jiffies */ extern u64 __cputime_jiffies_factor; @@ -89,6 +97,11 @@ static inline cputime_t jiffies_to_cputime(const unsigned long jif) return ct; } +static inline void setup_cputime_one_jiffy(void) +{ + cputime_one_jiffy = jiffies_to_cputime(1); +} + static inline cputime64_t jiffies64_to_cputime64(const u64 jif) { cputime_t ct; |