From 39613766e8826756a4bf8c74274eb971c3c1d929 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 15 Jan 2013 13:25:07 +0100 Subject: cputime: Librarize per nsecs resolution cputime definitions The full dynticks cputime accounting that we'll soon introduce will rely on sched_clock(). And its clock can have a per nanosecond granularity. To prepare for this, we need to have a cputime_t implementation that has this precision. ia64 virtual cputime accounting already uses that granularity so all we need is to librarize its implementation in the asm generic headers. Also librarize the default per jiffy granularity cputime_t as well so that we can easily pick either implementation depending on the cputime accounting config we choose. Signed-off-by: Frederic Weisbecker Cc: Andrew Morton Cc: Ingo Molnar Cc: Li Zhong Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Tony Luck Cc: Fenghua Yu --- include/asm-generic/cputime.h | 62 +------------------------------------------ 1 file changed, 1 insertion(+), 61 deletions(-) (limited to 'include/asm-generic/cputime.h') diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index 9a62937c56ca..c6eddf50eaf9 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -4,66 +4,6 @@ #include #include -typedef unsigned long __nocast cputime_t; - -#define cputime_one_jiffy jiffies_to_cputime(1) -#define cputime_to_jiffies(__ct) (__force unsigned long)(__ct) -#define cputime_to_scaled(__ct) (__ct) -#define jiffies_to_cputime(__hz) (__force cputime_t)(__hz) - -typedef u64 __nocast cputime64_t; - -#define cputime64_to_jiffies64(__ct) (__force u64)(__ct) -#define jiffies64_to_cputime64(__jif) (__force cputime64_t)(__jif) - -#define nsecs_to_cputime64(__ct) \ - jiffies64_to_cputime64(nsecs_to_jiffies64(__ct)) - - -/* - * Convert cputime to microseconds and back. - */ -#define cputime_to_usecs(__ct) \ - jiffies_to_usecs(cputime_to_jiffies(__ct)) -#define usecs_to_cputime(__usec) \ - jiffies_to_cputime(usecs_to_jiffies(__usec)) -#define usecs_to_cputime64(__usec) \ - jiffies64_to_cputime64(nsecs_to_jiffies64((__usec) * 1000)) - -/* - * Convert cputime to seconds and back. - */ -#define cputime_to_secs(jif) (cputime_to_jiffies(jif) / HZ) -#define secs_to_cputime(sec) jiffies_to_cputime((sec) * HZ) - -/* - * Convert cputime to timespec and back. - */ -#define timespec_to_cputime(__val) \ - jiffies_to_cputime(timespec_to_jiffies(__val)) -#define cputime_to_timespec(__ct,__val) \ - jiffies_to_timespec(cputime_to_jiffies(__ct),__val) - -/* - * Convert cputime to timeval and back. - */ -#define timeval_to_cputime(__val) \ - jiffies_to_cputime(timeval_to_jiffies(__val)) -#define cputime_to_timeval(__ct,__val) \ - jiffies_to_timeval(cputime_to_jiffies(__ct),__val) - -/* - * Convert cputime to clock and back. - */ -#define cputime_to_clock_t(__ct) \ - jiffies_to_clock_t(cputime_to_jiffies(__ct)) -#define clock_t_to_cputime(__x) \ - jiffies_to_cputime(clock_t_to_jiffies(__x)) - -/* - * Convert cputime64 to clock. - */ -#define cputime64_to_clock_t(__ct) \ - jiffies_64_to_clock_t(cputime64_to_jiffies64(__ct)) +#include #endif -- cgit v1.2.3 From abf917cd91cbb73952758f9741e2fa65002a48ee Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 25 Jul 2012 07:56:04 +0200 Subject: cputime: Generic on-demand virtual cputime accounting If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker Cc: Andrew Morton Cc: Ingo Molnar Cc: Li Zhong Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- include/asm-generic/cputime.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'include/asm-generic/cputime.h') diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index c6eddf50eaf9..51969436b8b8 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -4,6 +4,12 @@ #include #include -#include +#ifndef CONFIG_VIRT_CPU_ACCOUNTING +# include +#endif + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN +# include +#endif #endif -- cgit v1.2.3