linux-next/include/asm-generic/cputime.h

#ifndef _ASM_GENERIC_CPUTIME_H
#define _ASM_GENERIC_CPUTIME_H

#include <linux/time.h>
#include <linux/jiffies.h>

#ifndef CONFIG_VIRT_CPU_ACCOUNTING
# include <asm-generic/cputime_jiffies.h>
#endif

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
# include <asm-generic/cputime_nsecs.h>
#endif

#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 06:20:36 +08:00			`#ifndef _ASM_GENERIC_CPUTIME_H`
			`#define _ASM_GENERIC_CPUTIME_H`

			`#include <linux/time.h>`
			`#include <linux/jiffies.h>`

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 <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> 2012-07-25 13:56:04 +08:00			`#ifndef CONFIG_VIRT_CPU_ACCOUNTING`
			`# include <asm-generic/cputime_jiffies.h>`
			`#endif`

			`#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN`
			`# include <asm-generic/cputime_nsecs.h>`
			`#endif`
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! 2005-04-17 06:20:36 +08:00
			`#endif`