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linux/arch/ia64/include/asm/cputime.h

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[IA64] VIRT_CPU_ACCOUNTING (accurate cpu time accounting) This patch implements VIRT_CPU_ACCOUNTING for ia64, which enable us to use more accurate cpu time accounting. The VIRT_CPU_ACCOUNTING is an item of kernel config, which s390 and powerpc arch have. By turning this config on, these archs change the mechanism of cpu time accounting from tick-sampling based one to state-transition based one. The state-transition based accounting is done by checking time (cycle counter in processor) at every state-transition point, such as entrance/exit of kernel, interrupt, softirq etc. The difference between point to point is the actual time consumed during in the state. There is no doubt about that this value is more accurate than that of tick-sampling based accounting. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-01-29 05:27:30 +00:00
/*
[IA64] Move include/asm-ia64 to arch/ia64/include/asm After moving the the include files there were a few clean-ups: 1) Some files used #include <asm-ia64/xyz.h>, changed to <asm/xyz.h> 2) Some comments alerted maintainers to look at various header files to make matching updates if certain code were to be changed. Updated these comments to use the new include paths. 3) Some header files mentioned their own names in initial comments. Just deleted these self references. Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-08-01 17:13:32 +00:00
* Definitions for measuring cputime on ia64 machines.
[IA64] VIRT_CPU_ACCOUNTING (accurate cpu time accounting) This patch implements VIRT_CPU_ACCOUNTING for ia64, which enable us to use more accurate cpu time accounting. The VIRT_CPU_ACCOUNTING is an item of kernel config, which s390 and powerpc arch have. By turning this config on, these archs change the mechanism of cpu time accounting from tick-sampling based one to state-transition based one. The state-transition based accounting is done by checking time (cycle counter in processor) at every state-transition point, such as entrance/exit of kernel, interrupt, softirq etc. The difference between point to point is the actual time consumed during in the state. There is no doubt about that this value is more accurate than that of tick-sampling based accounting. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-01-29 05:27:30 +00:00
*
* Based on <asm-powerpc/cputime.h>.
*
* Copyright (C) 2007 FUJITSU LIMITED
* Copyright (C) 2007 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
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 05:56:04 +00:00
* If we have CONFIG_VIRT_CPU_ACCOUNTING_NATIVE, we measure cpu time in nsec.
[IA64] VIRT_CPU_ACCOUNTING (accurate cpu time accounting) This patch implements VIRT_CPU_ACCOUNTING for ia64, which enable us to use more accurate cpu time accounting. The VIRT_CPU_ACCOUNTING is an item of kernel config, which s390 and powerpc arch have. By turning this config on, these archs change the mechanism of cpu time accounting from tick-sampling based one to state-transition based one. The state-transition based accounting is done by checking time (cycle counter in processor) at every state-transition point, such as entrance/exit of kernel, interrupt, softirq etc. The difference between point to point is the actual time consumed during in the state. There is no doubt about that this value is more accurate than that of tick-sampling based accounting. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-01-29 05:27:30 +00:00
* Otherwise we measure cpu time in jiffies using the generic definitions.
*/
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!
2005-04-16 22:20:36 +00:00
#ifndef __IA64_CPUTIME_H
#define __IA64_CPUTIME_H
sched/cputime: Remove generic asm headers cputime_t is now only used by two architectures: * powerpc (when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y) * s390 And since the core doesn't use it anymore, we don't need any arch support from the others. So we can remove their stub implementations. A final cleanup would be to provide an efficient pure arch implementation of cputime_to_nsec() for s390 and powerpc and finally remove include/linux/cputime.h . Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1485832191-26889-36-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-31 03:09:51 +00:00
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
vtime: Consolidate a bit the ctx switch code On ia64 and powerpc, vtime context switch only consists in flushing system and user pending time, plus a few arch housekeeping. Consolidate that into a generic implementation. s390 is a special case because pending user and system time accounting there is hard to dissociate. So it's keeping its own implementation. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-11-13 23:24:25 +00:00
extern void arch_vtime_task_switch(struct task_struct *tsk);
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 05:56:04 +00:00
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
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 <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> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com>
2013-01-15 12:25:07 +00:00
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!
2005-04-16 22:20:36 +00:00
#endif /* __IA64_CPUTIME_H */
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